ArticlePDF Available

Abstract and Figures

Modern lineages of the beech family, Fagaceae, one of the most important north-temperate families of woody flowering plants, have been traced back to the early Eocene. In contrast, molecular differentiation patterns indicate that the Fagus lineage, Fagoideae, with a single modern genus, evolved much earlier than the remaining lineages within Fagaceae (Trigonobalanoideae, Castaneoideae, Quercoideae). The minimum age for this primary split in the Fagaceae has been estimated as 80 ± 20 Ma (i.e. Late Cretaceous) in recently published, time-calibrated phylogenetic trees including all Fagales. Here, we report fagaceous fossils from the Campanian of Wyoming (82–81 Ma; Eagle Formation [Fm]), the Danian of western Greenland (64–62 Ma; Agatdal Fm), and the middle Eocene of British Columbia (ca 48 Ma; Princeton Chert), and compare them to the Fagaceae diversity of the recently studied middle Eocene Hareøen Fm of western Greenland (42–40 Ma). The studied assemblages confirm that the Fagus lineage (= Fagoideae) and the remainder of modern Fagaceae were diverged by the middle Late Cretaceous, together with the extinct Fagaceae lineage(s) of Eotrigonobalanus and the newly recognised genus Paraquercus, a unique pollen morph with similarities to both Eotrigonobalanus and Quercus. The new records push back the origin of (modern) Fagus by 10 Ma and that of the earliest Fagoideae by 30 Ma. The earliest Fagoideae pollen from the Campanian of North America differs from its single modern genus Fagus by its markedly thicker pollen wall, a feature also seen in fossil and extant Castaneoideae. This suggests that a thick type 1 foot layer is also the plesiomorphic feature in Fagoideae although not seen in any of its living representatives. The Danian Fagus pollen of Greenland differs in size from those of modern species but is highly similar to that of the western North American early Eocene F. langevinii, the oldest known beech so far. Together with the Quercus pollen record, absent in the Campanian and Danian formations but represented by several types by the middle Eocene, this confirms recent dating estimates focussing on the genera Fagus and Quercus, while rejecting estimates from all-Fagales-dated trees as too young. The basic Castaneoideae pollen type, still found in species of all five extant genera of this putatively paraphyletic subfamily, represents the ancestral pollen type of most (modern) Fagaceae (Trigonobalanoideae, Castaneoideae, Quercoideae).
Content may be subject to copyright.
Acta Palaeobotanica 56(2): 247–305, 2016
DOI: 10.1515/acpa-2016-0016
Cretaceous and Paleogene Fagaceae
from North America and Greenland: evidence
for a Late Cretaceous split between Fagus
and the remaining Fagaceae
FRIÐGEIR GRÍMSSON
1, GUIDO W. GRIMM
1, REINHARD ZETTER
1 and THOMAS DENK
2
1 University of Vienna, Department of Palaeontology, Althanstraße 14 (UZA II), 1090 Vienna, Austria;
e-mails: fridgeir.grimsson@univie.ac.at; guido.grimm@univie.ac.at; reinhard.zetter@univie.ac.at
2 Swedish Museum of Natural History, Department of Palaeobiology, P.O.Box 50007, 10405 Stockholm,
Sweden; e-mail: thomas.denk@nrm.se
Received 28 August 2016; accepted for publication 24 October 2016
ABSTRACT. Modern lineages of the beech family, Fagaceae, one of the most important north-temperate fami-
lies of woody owering plants, have been traced back to the early Eocene. In contrast, molecular differentiation
patterns indicate that the Fagus lineage, Fagoideae, with a single modern genus, evolved much earlier than the
remaining lineages within Fagaceae (Trigonobalanoideae, Castaneoideae, Quercoideae). The minimum age for
this primary split in the Fagaceae has been estimated as 80 ± 20 Ma (i.e. Late Cretaceous) in recently published,
time-calibrated phylogenetic trees including all Fagales. Here, we report fagaceous fossils from the Campanian
of Wyoming (82–81 Ma; Eagle Formation [Fm]), the Danian of western Greenland (64–62 Ma; Agatdal Fm), and
the middle Eocene of British Columbia (ca 48 Ma; Princeton Chert), and compare them to the Fagaceae diversity
of the recently studied middle Eocene Hareøen Fm of western Greenland (42–40 Ma). The studied assemblages
conrm that the Fagus lineage (= Fagoideae) and the remainder of modern Fagaceae were diverged by the mid-
dle Late Cretaceous, together with the extinct Fagaceae lineage(s) of Eotrigonobalanus and the newly recognised
genus Paraquercus, a unique pollen morph with similarities to both Eotrigonobalanus and Quercus. The new
records push back the origin of (modern) Fagus by 10 Ma and that of the earliest Fagoideae by 30 Ma. The ear-
liest Fagoideae pollen from the Campanian of North America differs from its single modern genus Fagus by its
markedly thicker pollen wall, a feature also seen in fossil and extant Castaneoideae. This suggests that a thick
type 1 foot layer is also the plesiomorphic feature in Fagoideae although not seen in any of its living representa-
tives. The Danian Fagus pollen of Greenland differs in size from those of modern species but is highly similar
to that of the western North American early Eocene F. langevinii, the oldest known beech so far. Together with
the Quercus pollen record, absent in the Campanian and Danian formations but represented by several types
by the middle Eocene, this conrms recent dating estimates focussing on the genera Fagus and Quercus, while
rejecting estimates from all-Fagales-dated trees as too young. The basic Castaneoideae pollen type, still found
in species of all ve extant genera of this putatively paraphyletic subfamily, represents the ancestral pollen type
of most (modern) Fagaceae (Trigonobalanoideae, Castaneoideae, Quercoideae).
KEYWORDS: oldest modern Fagaceae, dispersed pollen, scanning electron microscopy, plant evolution, Campanian, Danian
INTRODUCTION
With ten genera, ve of which are monotypic
(Chrysolepis, Notholithocarpus, and the Trigo-
nobalanoideae Colombobalanus, Formano-
dendron, and Trigonobalanus), the Fagaceae
are a relatively small eudicot (eurosid) fam-
ily. Despite this, they are one of the most
important Northern Hemispheric tree families.
The family includes genera that are dominant
or common elements in mesophytic-temperate
forests (Castanea, Fagus, Quercus), commonly
are codominant in the Laurisilva (Castano-
psis, Quercus), or may be found as accessory
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
248 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
elements in tropical lowland and mid-altitude
forests (Castanopsis, few Quercus, Lithocar-
pus). Fagus and Quercus are among the most
economically important north-temperate decid-
uous trees. Oak (Quercus) is the largest tree
genus in the Northern Hemisphere, with more
than 400 accepted species. Except for the posi-
tion of Fagus as a genetically distinct sister to
the remainder of the family (Manos et al. 2001;
Fig. 1 based on the oligogene data used by Li
et al. 2004), the intergeneric relationships have
remained unclear to some degree (Manos et al.
2008, Oh & Manos 2008, Grimm & Denk 2010).
The main problem of molecular phylogenies
is that the signal in the commonly used chlo-
roplast data, also used in all-Fagales dating
approaches (Sauquet et al. 2012, Xiang et al.
2014, Xing et al. 2014, Larson-Johnson 2016),
appears to be decoupled from the systematic
and phylogenetic relationships in Fagaceae.
Highly similar to identical plastid haplotypes
can be found in different genera, and are com-
monly shared by otherwise distinct, based on
morphology and nuclear sequence data, evolu-
tionary lineages. This is well documented for the
largest genus Quercus at various levels (Kanno
et al. 2004, Neophytou et al. 2010, Simeone
et al. 2013, Simeone et al. 2016b), but also for
Fagus species in China (Zhang et al. 2013) and
Japan (Fujii et al. 2002). A similar situation is
found in Nothofagus (Acosta & Premoli 2010,
Premoli et al. 2012), a South American genus
of the Nothofagaceae, a family of four modern
genera (Heenan & Smissen 2013) representing
the rst branch in the Fagales subtree (Stevens
2001 onwards, Li et al. 2004, APG III 2009).
Hence, phylogenetic research on the largest
genus, Quercus, has increasingly focussed on
the nuclear genome (Manos et al. 2001, Denk
et al. 2005, Oh & Manos 2008, Grimm & Denk
2010, Hipp et al. 2014, Hubert et al. 2014, Hipp
and co-workers, work in progess). Essentially,
the compiled molecular data indicate that the
Castaneoideae (Castanea, Castanopsis, Chry-
solepis, Lithocarpus, Notholithocarpus) are
a paraphyletic group comprising genera more
(Castanea, Castanopsis, Notholithocarpus)
or less (Chrysolepis, Lithocarpus) close to Quer-
cus. The Eurasian Castanea and Castanopsis
are likely sister genera, and share plastids with
afnity to the ‘Old World’ or mid-latitude clade
of oaks (Quercus Group Cerris, Cyclobalanopsis
and Ilex), and Notholithocarpus is particularly
close to the ‘New World’ or high-latitude clade
of oaks (Quercus Group Lobatae, Protobalanus,
Quercus; Manos et al. 2008, Simeone et al.
2016b). The three monotypic trigonobalanoid
genera Colombobalanus, Formanodendron, and
Trigonobalanus, are strongly isolated from this
complex and from each other, and probably rep-
resent a species-depleted sister lineage to the
core Fagaceae, i.e. Castaneoideae + Quercoideae
(Manos et al. 2001, Manos et al. 2008, Oh
& Manos 2008, Grimm & Denk 2010). The
family’s type genus, Fagus (beech), is a distant
relative of the other Fagaceae: the phylogenetic-
genetic distance between Fagus and the most
recent common ancestor of all other Fagaceae is
equal to or higher than that between, for exam-
ple, Juglandaceae and Myricaceae or Betulaceae
and Ticodendraceae (monotypic)/Casuarinaceae
(Fig. 1, see also File S2*; Simeone et al. 2016a).
However, the oldest unambiguous records of
all modern genera with a studied fossil record
consistently fall into the same time, the Eocene
(see g. 14 in Grímsson et al. 2015).
Because of parallelisms and convergent
evolution, the rich macrofossil record of the
Fagaceae has been difcult to assess for molec-
ular dating analyses, particular when these are
exclusively based on chloroplast data that are
incongruent with relationships suggested by
nuclear sequences (e.g. Xiang et al. 2014, Lar-
son-Johnson 2016). On the other hand, pollen
morphologies are highly conserved within the
Fagaceae (Tab. 1), and diagnostic when stud-
ied using high-resolution scanning electron
microscopy (Praglowski 1982, 1984, Harada
et al. 2003, Denk & Grimm 2009b). The recog-
nition that pollen morphology is highly diag-
nostic for molecularly supported infrageneric
groups of oaks (Denk & Grimm 2009b) even-
tually led to the reconciliation of the fossil
record and molecular dating estimates (Hubert
et al. 2014, Grímsson et al. 2015). Remark-
ably, recent studies providing dated trees for
the Fagales (Sauquet et al. 2012, Xiang et al.
2014, Xing et al. 2014, Larson-Johnson 2016)
did not make use of the fossil pollen record
of Fagaceae or most other Fagales. Consider-
ing all available evidence (macro-, meso- and
microfossil record; phylogenetic relationships
inferred using nuclear data sets), it is clear
that the modern genera and main intrageneric
lineages of oaks were evolved by the Eocene
* File S2 available on page http://botany.pl/images/ibwyd/
acta_paleo/Acta_Paleobot_56_2_Grimsson_et_al_S2.pdf
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016 249
(Hubert et al. 2014, Grímsson et al. 2015;
and references therein) and that all modern
Fagaceae genera formed during the Paleogene.
Grímsson et al. (2015) documented a pol-
len ora rich in Fagaceae from the late mid-
dle to early late Eocene (42–40 Ma) Hareøen
Fm, Qeqertarsuatsiaq Is. (Hareøen), western
Greenland, including (i) Fagus, (ii) Eotrigo-
nobalanus, an extinct Fagaceae lineage, (iii)
representatives of the Castaneoideae includ-
ing pollen with afnity to modern species of
Castanea and possibly Castanopsis, and (iv)
several types of ancestral and derived (mod-
ern) oak (Quercus) pollen. Here we investigate
the diversity of Fagaceae in a ca 20 Ma older
formation from the same geographic region,
the Danian (early Paleocene), 64–62 Ma,
Agatdal Fm (Grímsson et al. 2016b), com-
plemented by palynological data from Cam-
panian and Eocene localities of (north-)west-
ern North America studied for the rst time
using SEM.
The earliest fossil record of Fagaceae dates
back to the Coniacian (Takahashi et al. 2008,
Denk & Tekleva 2014). Reproductive struc-
tures of Coniacian Fagaceae have pollen that
is very similar to modern pollen of Castane-
oideae. This pollen type continues to be the
most common Fagaceous pollen throughout
the Cretaceous and Paleocene. Therefore, we
were particularly interested in assessing the
pollen diversity of Fagaceae representing this
time period. We compare Campanian, Danian,
and Eocene Fagaceae assemblages and dis-
cuss possible biological afnities of the leaf
type Fagopsiphyllum. The likely convergent
evolution of deciduous leaves in the Fagaceae
at different time periods is briey discussed.
We recognise a new extinct Fagaceae genus,
Paraquercus, based on fossil pollen from the
Upper Cretaceous of Wyoming, and the Eocene
of British Columbia and western Greenland.
Our ndings are furthermore discussed in
the light of previously proposed molecular
Fig. 1. Phylogenetic inferences highlighting the absolute genetic relatedness of most Fagales genera, based on the matrix by
Li et al. (2004). Shown is a phylogenetic network based on model-based distances (right) and a traditional maximum likelihood
tree (left; values at branches indicate non-parametric bootstrap support from a partitioned and unpartitioned analysis). The
tree equals the cladogram shown in Li et al. (2004), which still is the basis for the classication of the order (Stevens 2001
onwards; APG III 2009). Note the substantial genetic (phylogenetic network) and phylogenetic distance (maximum likelihood
tree) between Fagus and other Fagaceae, matching that of interfamily distances in the rest of the Fagales. Selected minimum
age constraints used in all-Fagales dating studies are indicated. See File S2 for details on methodology and data
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
250 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
Table 1. Traditional classication and main pollen types of Fagaceae
Subfamily Status Genus Infrageneric group,
informal subgenus Shape P
(µm)
E
(µm) P/E P.v. Eq.v. Apertures Sculpturing (SEM) Reference
Fagoideae monophyletic Fagus Subgenus
Engleriana
spheroidal 28–37 32–33 0.86–1.11 convex triangular
to circular
circular
to elliptic
3-colporate irregular rugulate Praglowski 1982, Denk 2003
Subgenus Fagus spheroidal 33–42 35–44 0.86–1.14 convex triangular
to circular
circular
to elliptic
3-colporate irregular rugulate Praglowski 1982, Denk 2003
Trigonobalanoideae monophyletic Colombobalanus prolate 25–31 18–21 1.23–1.55 lobate to triangular
lobate
elliptic 3-colporoidate
(3-colpate)
(micro)verrucate, verrucae being fused
tufts and elongated
Nixon & Crepet 1989,
Wang et al. 1998
Formanodendron spheroidal 23–29 25–29 0.88–0.96 triangular circular
to elliptic
3-colporate (micro)verrucate, verrucae being fused
tufts and elongated
Wang & Chang 1988, Nixon
& Crepet 1989, Wang et al. 1998
Trigonobalanus spheroidal 25–28 23–26 1.10–1.18 circular to lobate circular
to elliptic
3-colporate granulate Nixon & Crepet 1989,
Wang et al. 1998
Castanoideae paraphyletic Castanea prolate 14–19 10–16 1.25–1.70 circular to lobate elliptic 3-colporate rugulate, perforate, fossulate Praglowski 1984
Castanopsis prolate 16–23 10–17 1.35–2.00 circular to lobate,
convex triangular
elliptic 3-colporate rugulate, perforate, fossulate, some
with secondary striation
Praglowski 1984
Chrysolepis prolate circular to lobate elliptic 3-colporate rugulate, perforate, fossulate Praglowski 1984
Lithocarpus prolate to
spheroidal
13–24 10–17 1.12–2.08 lobate to circular elliptic 3-colporate rugulate, fossulate Praglowski 1984
Notholithocarpus prolate 17–19 9–14 1.4 lobate to circular elliptic 3-colporate rugulate, fossulate Praglowski 1984,
Manos et al. 2008
Quercoideae probably mono-
phyletic
Quercus Group
Cyclobalanopsis
spheroidal 19–33 17–33 1.00–1.12 lobate to circular elliptic
to circular
3-colpate
(?3-colporoidate)
microechinate, microechini being the
tips of single rugulae (rodlike vertical)
Denk & Grimm 2009,
Denk & Tekleva 2014
Group Cerris spheroidal 26–40 24–38 1.05–1.08 lobate to circular elliptic
to circular
3-colpate
(?3-colporoidate)
verrucate, scattered verrucae being
simple tufts
Denk & Grimm 2009,
Denk & Tekleva 2014
Group Ilex spheroidal
to prolate
18–38 14–34 1.10–1.29 lobate to circular elliptic
to circular
3-colpate
(?3-colporoidate)
(micro)rugulate, perforate, microrugu-
lae agglomerate and form desert-rose-
like structures
Denk & Grimm 2009,
Denk & Tekleva 2014
Group Protobalanus prolate 20–30 14–23 1.30–1.43 lobate to circular elliptic 3-colpate
(?3-colporoidate)
(micro)verrucate, verrucae being
slightly convex tufts (rodlike masked)
Denk & Grimm 2009,
Denk & Tekleva 2014
Group Quercus spheroidal 23–50 21–46 1.07–1.10 lobate to circular elliptic
to circular
3-colpate
(?3-colporoidate)
(micro)verrucate, verrucae being single
or fused tufts
Denk & Grimm 2009,
Denk & Tekleva 2014
Group Lobatae prolate 36–42 22–26 1.60–1.63 lobate to circular elliptic 3-colpate
(?3-colporoidate)
(micro)verrucate, verrucae being single
or fused tufts
Denk & Grimm 2009,
Denk & Tekleva 2014
divergence estimates for the Fagaceae subtree,
which vary remarkably depending on the data
sets used for inference (Tab. 2).
MATERIAL AND METHODS
PALAEOPALYNOLOGICAL SAMPLES
The investigated material originates from four dif-
ferent localities: the Late Cretaceous (Campanian)
Eagle Fm, Elk Basin, Wyoming (palynological samples);
the early Paleocene (Danian) Agatdal Fm (and/or Eqalu-
lik Fm), Nuussuaq Basin, western Greenland (macrofos-
sils and palynological samples); the middle Eocene (late
Ypresian) Allenby Fm, Princeton Basin, British Colum-
bia (palynological samples); and the middle Eocene (lat-
est Lutetian, early Bartonian) Hareøen Fm (macrofos-
sils and palynological samples), Nuussuaq Basin.
GEOLOGICAL BACKGROUND
The Elk Basin is a valley bordering the Wyoming-
Montana state boundary in the north-western United
States (44°59ʹN/108°52ʹW; see File S1**). The Elk
** File S1 available on page http://botany.pl/images/ibwyd/
acta_paleo/Acta_Paleobot_56_2_Grimsson_et_al_S1.pdf
Basin is a breached and eroded anticline comprising
several outcrops with both marine and terrestrial
Upper Cretaceous to Paleogene sedimentary rocks.
The Campanian Eagle Fm is divided into two units:
a lower unit, the Virgelle Sandstone Member and an
upper unit, the Upper Eagle Beds (Hicks 1993, Van
Boskirk 1998). All plant macrofossils described by Van
Boskirk (1998) and the palynological samples used for
this study originate from the upper part of the Upper
Eagle Beds. Biostratigraphic, magnetostratigraphic,
and chronometric dating studies (see Hicks 1993, Van
Boskirk 1998) suggest that the plant-bearing unit of
the Eagle Fm is of early Campanian age (82–81 Ma).
For a more detailed geological background and pre-
vious work on the palaeoora see Hicks (1993), Van
Boskirk (1998), and Manchester et al. (2015).
The material of the early Paleocene (Danian) Agat-
dal Fm (and/or Eqalulik Fm) of the Nuussuaq Basin
originates from the Agatdalen valley, situated in the
central part of the Nuussuaq Peninsula, western
Greenland. Pollen was extracted from phosphoritic
nodules from the Agatdal Fm found at Turritellakløft
(Big section). The macrofossils are from three locali-
ties: the Agatkløft and Qaarsutjægerdal (Big section)
localities, Agatdal Fm, and the Kangersooq (Quleru-
arsuup isua) locality representing either the Agatdal
Fm or the slightly younger Eqalulik Fm. Magneto-
stratigraphic and chronometric dating of overlying
and interspersing volcanic strata indicate an age of
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016 251
64–62 Ma for the Agatdal Fm and 62–61 Ma for the
overlying Eqalulik Fm. For a detailed geological back-
ground (including maps), stratigraphic framework
(including proles), position of outcrops, age corre-
lations, collection history, previous palaeobotanical
work, origin of macrofossils and phosphoritic nodules,
and laboratory treatment of palynological samples see
Grímsson et al. (2016b).
In the Princeton Basin, an outcrop of the middle
Eocene Allenby Fm, the upper part of the Princeton
Group, is located along the east bank of the Similka-
meen River, ca 8.4 km south of the town of Prince-
ton, British Columbia, Canada (49°22ʹN, 120°32ʹW;
see File S1). The uppermost part of the Allenby Fm,
the Ashnola Shale, comprises silicied and fossil-rich
sedimentary rocks known as the Princeton Chert beds
(Read 2000, Smith & Stockey 2007, Mustoe 2011). The
Princeton Chert is composed of at least 49 rhythmically
bedded chert beds and carbonaceous interbeds (Mustoe
2011). Our samples originate from chert-bed 43, from
the uppermost quarter of the Princeton Chert unit. The
age of the Princeton Chert is not fully settled (Fig. S3 in
File S1), with older K-Ar dates indicating younger ages
than more recent U-Pb dates for several localities of the
Okanagan belt (Denk & Dillhoff 2005 for McAbee; Moss
et al. 2005 for a general overview). With respect to the
stratigraphic position of the Princeton Chert beds in the
uppermost part of the Allenby Fm, we follow Moss et al.
(2005, g. 2) and assume an age of ca 48 Ma.
The late Lutetian-early Bartonian Hareøen Fm crops
out at the Aamaruutissa locality on the island of Qeqer-
tarsuatsiaq, western Greenland. The palynological sam-
ples originate from a resinite-rich coal bed in the lowest
part of the sedimentary succession, and the macrofossils
were collected in the lowest, middle and uppermost part
of the succession (see g. 5 in Grímsson et al. 2015). The
sediments comprising the plant fossils are considered to
be ca 42–40 Ma, based on chronometric dating of overly-
ing lavas (38.74±0.23 Ma; Larsen et al. 2015) and the pol-
len/spore spectrum. For a detailed geological background,
stratigraphic framework, and information on previous
palaeobotanical work see (Grímsson et al. 2015).
SAMPLE PREPARATION
AND THE SINGLE-GRAIN METHOD
The palynological samples were processed accord-
ing to the protocols outlined in Grímsson et al. (2008;
sediments), Grímsson et al. (2011; nodules), and Denk
et al. (2012; nodules). All fossil pollen grains were
studied by both light and electron microscopy using
the single-grain method by Zetter (1989).
CONSERVATION OF FOSSIL MATERIAL
All the macrofossils gured and mentioned in this
study from Agatdalen are housed in the collection of
the Geological Museum in Copenhagen (MGUH) that
Table 1. Traditional classication and main pollen types of Fagaceae
Subfamily Status Genus Infrageneric group,
informal subgenus Shape P
(µm)
E
(µm) P/E P.v. Eq.v. Apertures Sculpturing (SEM) Reference
Fagoideae monophyletic Fagus Subgenus
Engleriana
spheroidal 28–37 32–33 0.86–1.11 convex triangular
to circular
circular
to elliptic
3-colporate irregular rugulate Praglowski 1982, Denk 2003
Subgenus Fagus spheroidal 33–42 35–44 0.86–1.14 convex triangular
to circular
circular
to elliptic
3-colporate irregular rugulate Praglowski 1982, Denk 2003
Trigonobalanoideae monophyletic Colombobalanus prolate 25–31 18–21 1.23–1.55 lobate to triangular
lobate
elliptic 3-colporoidate
(3-colpate)
(micro)verrucate, verrucae being fused
tufts and elongated
Nixon & Crepet 1989,
Wang et al. 1998
Formanodendron spheroidal 23–29 25–29 0.88–0.96 triangular circular
to elliptic
3-colporate (micro)verrucate, verrucae being fused
tufts and elongated
Wang & Chang 1988, Nixon
& Crepet 1989, Wang et al. 1998
Trigonobalanus spheroidal 25–28 23–26 1.10–1.18 circular to lobate circular
to elliptic
3-colporate granulate Nixon & Crepet 1989,
Wang et al. 1998
Castanoideae paraphyletic Castanea prolate 14–19 10–16 1.25–1.70 circular to lobate elliptic 3-colporate rugulate, perforate, fossulate Praglowski 1984
Castanopsis prolate 16–23 10–17 1.35–2.00 circular to lobate,
convex triangular
elliptic 3-colporate rugulate, perforate, fossulate, some
with secondary striation
Praglowski 1984
Chrysolepis prolate circular to lobate elliptic 3-colporate rugulate, perforate, fossulate Praglowski 1984
Lithocarpus prolate to
spheroidal
13–24 10–17 1.12–2.08 lobate to circular elliptic 3-colporate rugulate, fossulate Praglowski 1984
Notholithocarpus prolate 17–19 9–14 1.4 lobate to circular elliptic 3-colporate rugulate, fossulate Praglowski 1984,
Manos et al. 2008
Quercoideae probably mono-
phyletic
Quercus Group
Cyclobalanopsis
spheroidal 19–33 17–33 1.00–1.12 lobate to circular elliptic
to circular
3-colpate
(?3-colporoidate)
microechinate, microechini being the
tips of single rugulae (rodlike vertical)
Denk & Grimm 2009,
Denk & Tekleva 2014
Group Cerris spheroidal 26–40 24–38 1.05–1.08 lobate to circular elliptic
to circular
3-colpate
(?3-colporoidate)
verrucate, scattered verrucae being
simple tufts
Denk & Grimm 2009,
Denk & Tekleva 2014
Group Ilex spheroidal
to prolate
18–38 14–34 1.10–1.29 lobate to circular elliptic
to circular
3-colpate
(?3-colporoidate)
(micro)rugulate, perforate, microrugu-
lae agglomerate and form desert-rose-
like structures
Denk & Grimm 2009,
Denk & Tekleva 2014
Group Protobalanus prolate 20–30 14–23 1.30–1.43 lobate to circular elliptic 3-colpate
(?3-colporoidate)
(micro)verrucate, verrucae being
slightly convex tufts (rodlike masked)
Denk & Grimm 2009,
Denk & Tekleva 2014
Group Quercus spheroidal 23–50 21–46 1.07–1.10 lobate to circular elliptic
to circular
3-colpate
(?3-colporoidate)
(micro)verrucate, verrucae being single
or fused tufts
Denk & Grimm 2009,
Denk & Tekleva 2014
Group Lobatae prolate 36–42 22–26 1.60–1.63 lobate to circular elliptic 3-colpate
(?3-colporoidate)
(micro)verrucate, verrucae being single
or fused tufts
Denk & Grimm 2009,
Denk & Tekleva 2014
Table 1.Continued
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
252 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
is part of the Natural History Museum of Denmark.
The macrofossils from Qeqertarsuatsiaq are also
housed in the Copenhagen museum or in the collec-
tion of the Swedish Museum of Natural History in
Stockholm (S). Numbers of the Copenhagen specimens
sometimes refer to a single fossil, or part and counter-
part, or a block with several fossils, or part and coun-
terpart blocks with numerous fossils. Hence, different
fossil leaves gured here can have the same MGUH
number when occurring on the same hand-specimen
or accompanying counterpart. SEM stubs with pollen
produced under this study are stored in the collec-
tion of the Department of Palaeontology, University
of Vienna, Austria, under accession numbers IPUW
7513/161–208.
POLLEN AND MACROFOSSIL DESCRIPTIONS
Terminology for angiosperm leaf morphology fol-
lows mostly Hickey (1973) and Ellis et al. (2009).
The pollen descriptions include diagnostic features
observed under LM and SEM, with terminology fol-
lowing Punt et al. (2007) and Hesse et al. (2009). All
measurements of polar axis and equatorial diameter
were made in LM. Plates showing dispersed pollen
grains exhibit the same individual pollen grain pho-
tographed with LM, usually in polar and equatorial
view, and SEM, overview and close-up displaying the
characteristic sculpture of the pollen surface.
SYSTEMATIC PALAEOBOTANY
The description starts with extinct gen-
era in alphabetical order, followed by extant
genera arranged according to alphabetical
order of subfamilies. When present, leaves are
described after the corresponding pollen. Leaf
descriptions are based on all fossil specimens
encountered from the particular formation(s).
Synonym lists include only taxa/specimens
previously described from the same localities/
formations. Pollen types (PT) and leaf mor-
photypes (LMT) are labelled by the taxonomic
rank (family, subfamily, genus) to which they
can be assigned.
Family FAGACEAE Dumort.
Genus Eotrigonobalanus
Walther & Kvaček (extinct)
Eotrigonobalanus PT
Pl. 1, gs 4–6; Pl. 3, gs 1–6; Pl. 12, gs 4–6
D e s c r i p t i o n. Pollen, monad, prolate, circu-
lar to lobate in polar view, elliptic in equato-
rial view; polar axis 17–23 µm long, equato-
rial diameter 12–16 µm; tricolporate, colpi
long, pori elongated rectangular (lalongate),
nexine slightly thickened around pori (LM);
exine 0.8–1.2 µm thick, nexine slightly thinner
than sexine; tectate; sculpture scabrate in LM,
microrugulate, perforate in SEM, microrugu-
lae twisted and interwoven, microrugulae 0.3–
1.1 µm long, 80–170 nm wide, microrugulae
fused forming larger rope-like rugulae (SEM).
L o c a l i t i e s / a g e. Elk Basin, Wyoming (82–
81 Ma); Turritellakløft (Big section; Agatda-
len), western Greenland (64–62 Ma); Prin-
ceton Chert, British Columbia (ca 48 Ma);
Qeqertarsuatsiaq, western Greenland (42–
40 Ma; Grímsson et al. 2015, gs 6a–f).
R e m a r k s. Very similar to identical dis-
persed fossil pollen grains have been docu-
mented from the Paleocene/Eocene boundary
of Salzburg, Austria (Hofmann 2010, Hofmann
et al. 2011), the early Oligocene of Cospuden,
Table 2. Divergence ages for the Fagaceae subtree published in the last ve years. Abbreviations: FBD – fossilised birth-death
dating, ND – node dating, PL – penalised likelihood, TE – total evidence dating, UC – uncorrelated clock
Study Taxon set Fagus root age Fagus crown
age
Castanoideae
crown age Quercus root age
Sauquet et al. (2012), “safe” ingroup
and outgroup constraints; PL-ND all Fagales 82.3 (89–76.2) [N/A] [xed to 43.8] [not reported]
—; UC-ND (log-normal priors) all Fagales 84.7 (103.6–64.2) [N/A] 48.7 (58.1–43.8) 31.4 (interval not
reported)
Xing et al. (2014); UC-ND (uniform
priors) all Fagales 83.4 (97.8–65.5) 16.2 (24–9) 46.2 (56.3–37.2) ~ 36 (interval not
reported)
—; UC-ND (log-normal priors) all Fagales 68.1 (85.5–64) 15.7 (18.5–8.42) 37.2 (38.1–37.2) [not reported]
Xiang et al. (2014); UC-ND all Fagales 82.8 (87.1–76.6) 17.2 (24.2–7.9) 56.4 (66.1–50.6) [= Castanoideae
crown]
Larson-Johnson (2016), TE all Fagales 78 (88–70) [N/A] 47 (53–44) 20 (31–9)
Hubert et al. (2014), constraint 1
(best overall t); UC-ND
Quercus and
sister taxa [N/A] [N/A] [N/A] 54 (68–48)
Renner et al. (2016); FBD Fagus [N/A] 53 (62–43) [N/A] [N/A]
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016 253
Germany, as E. eiszmannii Walther & Kvaček
(Denk et al. 2012), and from middle Miocene
sediments of Poland (Kohlman-Adamska
& Ziembińska-Tworzydło 2000, Stuchlik et al.
2007). The same type of pollen has also been
described from clumps attached to fossil leaves
of Eotrigonobalanus furcinervis from the Oli-
gocene of Witznitz, Germany, hence its generic
association (Walther & Zetter 1993). The pol-
len grains presented here represent the oldest
reports of Eotrigonobalanus so far.
Pollen found in-situ in catkins described as
Amentoplexipollenites catahoulaensis Crepet
& Nixon from the middle to late Oligocene of
Texas (Crepet & Nixon 1989) is indistinguish-
able from pollen of Eotrigonobalanus regard-
ing its size, form, and sculpture. Amentoplexi-
pollenites catahoulaensis mainly differs from
Eotrigonobalanus PT by its much thicker nex-
ine. The inorescence has been related to the
modern genus Trigonobalanopsis.
Eotrigonobalanus leaf morphotype
Pl. 4, gs 1–6; Pl. 5, gs 1–9
1963 Quercophyllum furcinervis americana (Rossm.)
Knowlton – Koch: p. 37, pl. 6, gs 4–6, pl. 7, gs
1–3.
1963 Cupuliferites angmartusuticus Koch – p. 40, pl.
8, g. 4, pl. 9, g. 1, pl. 10, gs 1, 2.
1963 Quercus drymeia Unger – Koch: p. 94, pl. 51, gs
2, 3.
M a t e r i a l. Specimens MGUH 10376, MGUH
10377, MGUH 10378, MGUH 10379, MGUH
10380, MGUH 10383, MGUH 10384, MGUH
10385, MGUH 10386, MGUH 10388, MGUH
10461, MGUH 10461, MGUH 10462, MGUH
10462.
D e s c r i p t i o n. Leaves petiolate, petiole up
to 27 mm long, lamina simple, 45 to 160 mm
long, 14 to 62 mm wide, length/width ratio 2.4
to 6.2, widest in second and third quartile of
lamina; lamina narrow ovate, narrow ellip-
tic, to oblanceolate, apex acute, base acute to
decurrent, margin partially or entirely toothed;
teeth dentate to serrate, small to large, basal
side much longer than apical side, basal side
mostly convex, apical side mostly concave or
straight, tooth apex simple to spinose, sinuses
between teeth wide and rounded, teeth served
by secondary veins, one tooth per secondary
vein; primary venation pinnate, moderate in
thickness, rarely stout, straight to gently cur-
ved; secondary venation craspedodromous,
secondary veins moderate in thickness,
straight to gently curved upwards, occasio-
nally curving outwards when entering teeth,
7 to 12 pairs diverging from midvein at inter-
vals of 9 to 18 mm in middle part of lamina,
arising at angles of 30° to 50° from midvein,
occasionally more acute on one side of lamina,
usually alternate, occasionally subopposite at
leaf base.
L o c a li t i e s/ a g e. Agatkløft (Agatdalen), west-
ern Greenland (64–62 Ma); Kangersooq (Qul-
erarsuup isua, Agatdalen), western Greenland
(64–62 or 62–61 Ma); Qaarsutjægerdal (Big sec-
tion, Agatdalen), western Greenland (64–62 Ma).
Remarks. Eotrigonobalanus is a well-known
extinct genus comprising extremely heteroge-
neous leaf forms occurring mostly in middle
Eocene to early Oligocene sediments of Europe
(e.g. Kvaček & Walther 1989, Palamarev
& Mai 1998) and extending to the Miocene
(e.g. Velitzelos et al. 2014). The leaves from
the Agatdalen area show the same morphologi-
cal variability as observed in European Paleo-
gene oras and are among the earliest records
of this genus.
Genus Fagopsiphyllum Manchester (extinct)
Fagopsiphyllum groenlandicum
(Heer) Manchester
Pl. 6, gs 1–8; Pl. 7, gs 1–8; Pl. 14, g. 3; Pl. 15, gs 1–6
1883 Quercus grönlandica Heer – p. 89, pl. 89, gs 4,
8; pl. 91, g. 1.
1963 Quercophyllum groenlandicus (Heer) Koch – p.
34, pl. 5, gs 1–4; pl. 6, gs 1–3.
M a t e r i a l. Specimens MGUH 6538, MGUH
6542, MGUH 10369, MGUH 10370, MGUH
10371, MGUH 10372, MGUH 10373, MGUH
10374, MGUH 10375, MGUH 10397, MGUH
10411, MGUH 10428, MGUH 10437.
D e s c r i p t i o n. Leaves petiolate, petiole short,
up to 5 mm long, lamina simple, 40 to 130 mm
long, 21 to 96 mm wide, length/width ratio 1.9
to 2.1, lamina elliptic, apex acute, base decur-
rent to obtuse, margin toothed, teeth dentate to
serrate, large, teeth of similar size and shape,
basal side equal to twice as long as apical
side, basal side convex to straight, apical side
straight to convex, tooth apex simple with non-
glandular, nonspinose apices, sinuses between
teeth narrow to wide angular, teeth occurring
at regular intervals, served by secondary veins,
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
254 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
one tooth per secondary vein; primary venation
strictly regularly pinnate, midvein moderate in
thickness, straight to gently curved; secondary
venation craspedodromous, secondary veins of
moderate thickness, evenly spaced, parallel,
mostly straight, occasionally slightly recurved
at base, sometimes curving upwards when
entering teeth, 12 to 18 pairs diverging from
midvein at intervals of 3.5 to 12 mm in mid-
dle of lamina, arising at angles of 40° to 65°
from midvein, sometimes more acute on one
side of the lamina, opposite to alternate, each
secondary vein terminating in a marginal tooth;
pair of narrow basal veins (opadial veins) run-
ning along base margin, not serving teeth; ter-
tiary venation percurrent, veins mostly simple,
sometimes branched, straight to sinuous, 5 to 7
tertiary veins per 1 cm secondary vein in large
leaves, originating at right angles from both the
admedial and exmedial side of secondary veins.
N o t e. The most typical leaf fossils of this
type are allegedly from Qeqertarsuatsiaq (old
name: Hareøen; Pl. 15, gs 1–5) and were rst
described by Heer (1883, pl. 89, gs 4 [MGUH
6538], 8 [MGUH 6542]). Inspection by FG of all
museum specimens from the Cainozoic of west-
ern Greenland (housed in Copenhagen, Dublin,
London, Stockholm) suggests that these speci-
mens are not from Qeqertarsuatsiaq: the sedi-
ment in which these fossils are preserved does
not correspond to any material with a genuine
“Hareøen” (Danish for Qeqertarsuatsiaq) local-
ity/collecting label, but looks identical to that
known from the Upper Atanikerluk A local-
ity (Quikavsak Fm; same age as Agatdal Fm)
situated on the south coast of Nuussuaq. The
MGUH 6542 specimen has an original Atani-
kerluk locality/collecting label that somehow
must have been missed by Heer; the MGUH
6538 specimen has no locality/collecting label.
Genuine “Hareøen” specimens in the Copen-
hagen collection described by Heer (1883) are
all from the same collector (Knud Johannes
Vogelius Steenstrup) and have a corresponding
locality/collecting label signed with the initials
KJVS. Specimen MGUH 6534 from Qeqertar-
suatsiaq identied as Quercus grönlandica by
Heer (1883, pl. 89, g. 1a) has no margin or apex
preserved and is of uncertain afnity, and is not
included in our synonym list for this locality.
The only convincing Fagopsiphyllum leaf fossil
from Qeqertarsuatsiaq is specimen MGUH 6550
(see Pl. 14, g. 3; Pl. 15, g. 6; also pl. 91, g. 1
in Heer 1883). Additional large-leaved Fagales/
Fagaceae also occur in Qeqertarsuatsiaq (or
Upper Atanikerluk A), but their venation and
dentition differs from those of Fagopsiphyllum:
some have rounded sinuses between teeth (Pl.
14, gs 1, 2), others also have secondary teeth
present (Pl. 14, g. 4; Pl. 15, g. 7).
L o c a l i t i e s / a g e. Kangersooq (Qulerarsuup
isua, Agatdalen), western Greenland (64–62
or 62–61 Ma); Upper Atanikerluk A (south
coast of Nuussuaq), western Greenland (64–
62 Ma); Qeqertarsuatsiaq, western Greenland
(42–40 Ma).
R e m a r k s. The leaf fossils from Agatdalen
were originally described as Quercophyllum
groenlandicus by Koch (1963). The form of the
leaves and their venation is strikingly similar
to fossil leaves originally assigned to the extinct
genus Fagopsis described from the late Eocene
of Colorado, USA (e.g. Manchester & Crane
1983). As a result, the Agatdalen material was
included into Fagopsis by Boulter & Kvaček
(1989) along with material from the Paleocene
of the Isle of Mull. Manchester later excluded
Paleocene leaves of this type from high arctic
areas from Fagopsis and placed them within
their own genus, Fagopsiphyllum (Manches-
ter 1999), based on the observation that the
distinctive fruits of Fagopsis have never been
found in any of the Paleocene high arctic
material (Heer 1868, Brown 1962, Koch 1963,
Manchester & Crane 1983, Boulter & Kvaček
1989) from North America, Greenland, and the
British Isles. Recently, Bouchal et al. (2014)
described the characteristic pollen, both in situ
from staminate inorescenses and dispersed,
of Fagopsis from its type locality using SEM,
a pollen type not found in the Paleocene of
Agatdalen. The lack of the diagnostic fruits
and pollen of Fagopsis in the Greenland mate-
rial provides further support for Manchester’s
(1999) opinion that these leaves belong to
a different taxon.
Genus Paraquercus gen. nov. (extinct)
D i a g n o s i s. Fagaceae pollen; rugulate with
distinctive verrucate suprasculpture; verrucae
composed of very narrow, rod-like, regularly
arranged rugulae, giving the pollen surface
the appearance of a nely braided clew of yarn;
rugulae in groups, not or rarely intertwining,
parallel to radially arranged (oriented).
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016 255
E t y m o l o g y. Referring to the basic simila-
rity of the pollen ornamentation with that of
the putatively ancestral (plesiomorphic) pollen
type of Quercus, pollen of Quercus Group Ilex,
while not being produced by an oak.
Type species. Paraquercus campania sp.
nov.
G e n era l r e mar k s. Originally (Grímsson
et al. 2015), we considered the pollen found
in the Eocene Hareøen Fm (Quercus sp. 5,
included here in the new species Paraquercus
eocaena) to represent a relatively ancestral,
extinct lineage of oaks, as it shares the basic
organisation of pollen of Quercus Group Ilex,
which represents the ancestral (plesiomorphic)
oak pollen type (Denk & Grimm 2009b), and
lacks the characteristics of pollen of Eotrigo-
nobalanus (Tab. 1). The latter is the Fagaceae
genus which, regarding pollen morphology, is
most similar to pollen of oaks. Because the
new pollen from the Campanian Eagle Fm and
the Lutetian (middle Eocene) Princeton Chert
clearly belongs to the same lineage as the pol-
len grain reported earlier from Qeqertarsuat-
siaq, Greenland, an association of this pollen
type with Quercus appears highly unlikely (dis-
cussed below). We regard the differences from
pollen of Eotrigonobalanus sufcient to erect
a new genus, but do not exclude the possibility
that both extinct genera belong to the same
evolutionary lineage. Furthermore, pollen of
the extinct Fagaceae genera Eotrigonobala-
nus, Fagopsis, and Trigonobalanopsis, among
others, have been linked to macrofossils, which
at this point is not possible for Paraquercus.
Paraquercus campania sp. nov.
Pl. 1, gs 1–3
D i a g n o s i s. Space between (micro)rugulae
partly obscured by sporopollenin; from the
Cretaceous.
H o l oty p e. IPUW 7513/161 (Pl. 1, gs 1–3).
T y p e l o c a l i t y. Elk Basin, Wyoming,
boundary to Montana; ca 44° 59ʹ N, 108° 52ʹ W.
S t r a t i g r a p h y. Upper Eagle beds, Eagle Fm
(File S1)
A g e. 82–81 Ma
S p e c i e s e p i t h e t. After the time period of
the pollen-bearing sedimentary rocks.
D e s c r i p t i o n. Pollen, monad, prolate, lobate in
polar view, elliptic in equatorial view; polar axis
20–21 µm long, equatorial diameter 15–16 µm;
tricolporate, colpi long, pori lalongate, nexine
slightly thickened around pori (LM); exine 0.9–
1.0 µm thick, nexine thinner or as thick as sexine
(LM); tectate; sculpture scabrate to verrucate
in LM, verrucate, (micro)rugulate, perforate in
SEM, verrucae composed of very narrow rod-
like (micro)rugulae, (micro)rugulae 0.5–1.3 µm
long, 80–110 nm wide, (micro)rugulae in groups,
parallel to radially arranged (SEM).
Remarks. Paraquercus campania represents
one of the earliest reports of Fagaceae. It dif-
fers from its 30–40 Ma younger counterparts
(P. eocaena) by showing a less delicate pol-
len surface (rugulae less distinct in general,
fewer perforations). Paraquercus pollen is very
similar to pollen of Eotrigonobalanus but dif-
fers mainly in the sculpture type. The (micro)
rugulae are usually much longer in Paraquer-
cus and they are arranged into large verru-
cate units, but form narrower/oblong rope-like
rugulate units in Eotrigonobalanus (SEM).
Paraquercus eocaena sp. nov.
Pl. 12, gs 1–3
2015 Quercus sp. 5 – Grímsson et al.: p. 827, gs 15a–c.
D ia g no si s. Space between (micro)rugulae not
obscured by sporopollenin; from the Paleogene.
H o l oty p e. IPUW 7513/197 (Pl. 12, gs 1–3).
T y p e l o c a l i t y. Princeton Chert, Princeton
Basin, British Columbia, Canada; ca 49°22ʹN,
120°33ʹW.
S t rat i g rap h y. Princeton Chert bed 43, Ash-
nola Shale (informal), Allenby Fm, Princeton
Group (File S1).
A g e. ca 48 Ma.
S p e c i e s e p i t h e t. After the time period of
the pollen-bearing sedimentary rocks.
D e s c r i p t i o n. Pollen, monad, prolate, lobate
in polar view, elliptic in equatorial view; polar
axis 17–25 µm long, equatorial diameter
15–19 µm; tricolporate, colpi long, pori lalon-
gate, nexine slightly thickened around pori
(LM); exine 1.0–1.6 µm thick, nexine thinner
or as thick as sexine (LM); tectate; sculpture
scabrate to verrucate in LM, verrucate, (micro)
rugulate, perforate in SEM, verrucae composed
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
256 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
of very narrow rodlike (micro)rugulae, (micro)
rugulae 0.5–2.1 µm long, 90–140 nm wide,
rugulae in groups, parallel to radially arran-
ged (SEM).
R e m a r k s. In the Princeton Chert specimens
the characteristic pollen surface is more distinct
than in its older relative, Paraquercus campania,
a feature we consider to be an original difference
of the grains and not caused by taphonomic pro-
cesses during fossilization. Also, the rugulae can
be much longer in P. eocaena, up to 2.1 µm vs
1.3 µm in P. campania). This pollen type is also
known from slightly younger (42–40 Ma) sedi-
ments of Qeqertarsuatsiaq, western Greenland
(see gs 15a–c in Grímsson et al. 2015).
Genus Trigonobalanopsis Kvaček et
H.Walther (extinct)
Trigonobalanopsis PT
Pl. 12, gs 7–13
D e scr i pti o n. Pollen, monad, prolate, outline
lobate in polar view, elliptic in equatorial view;
polar axis 18–22 µm long, equatorial diameter
13–16 µm; tricolporate, colpi long, pori small
and circular, nexine slightly thickened around
pori; exine 0.8–1.0 µm thick, nexine as thick
or slightly thicker than sexine (LM); tectate;
sculpture psilate in LM, rugulate to microru-
gulate, perforate in SEM, rugulae irregularly
arranged or parallel in small groups, rugulae
0.5–1.5 µm long, 80–140 nm wide, rugulae con-
spicuously segmented (SEM).
L o c a l i t y / a g e. Princeton Chert, British
Columbia (ca 48 Ma).
R e ma r ks. Numerous fossil leaves and cupules/
fruits of Trigonobalanopsis have been docu-
mented from Europe and the western part of
Russia from late Eocene to Pliocene sediments
(summarised in Kvaček & Walther 1988, 1989,
Palamarev & Mai 1998). The pollen type belong-
ing to this extinct genus was rst described by
Walther & Zetter (1993) using pollen clumps
adhering to the laminar surface of a Trigono-
balanopsis leaf. Dispersed Trigonobalanopsis
pollen grains have been reported from the early
Oligocene of Germany (Denk et al. 2012), the
early and late Miocene of Austria (Meller et al.
1999, Grímsson et al. 2016a) and the late Mio-
cene of Iceland (Denk et al. 2011). The pollen
grains presented here are the rst and only
reports of Trigonobalanopsis from North Amer-
ica, and the earliest pollen record of this genus
worldwide. However, the same pollen type can
also be found in latest Cretaceous (Timerdyakh
Fm; latest Campanian to earliest Maastrich-
tian; Hofmann & Zetter 2007, 2010) Siberian
sediments outcropping at the Tyung River of the
Vilui Basin (C.-C. Hofmann, pers. comm., 2016).
Subfamily CASTANEOIDEAE Oerst.
Genus indet.
Castaneoideae PT 1
Pl. 1, gs 7–9
D e s c r i p t i o n. Pollen, monad, prolate, out-
line lobate in polar view, elliptic in equatorial
view; polar axis 14–15 µm long, equatorial dia-
meter 10–11 µm; tricolporate; colpi long, pori
small and lolongate; exine 0.9–1.1 µm thick
(LM), nexine thinner than sexine; tectate;
sculpture psilate in LM, rugulate, fossulate,
perforate in SEM; rugulae densely packed,
irregularly arranged, 100–230 nm wide, stout,
sinuous and often branched (bifurcating), with
the branches running parallel, rugulae equally
developed across entire pollen grain (SEM).
L o c a l i t y / a g e. Elk Basin, Wyoming (82–
81 Ma).
R e m a r k s. Recent Castaneoideae pollen
grains have been studied using LM, SEM, and
TEM by e.g. Praglowski (1984) and Wang & Pu
(2004). Although the pollen grains of PT 1 fall
within the general type of Castaneoideae pol-
len, its particular sculpture pattern distin-
guishes it from its modern counterparts. Pollen
of extant Castaneoideae can vary substantially
in the arrangement and length of rugulae and
the distinctness of fossulae separating these. In
Castaneoideae PT 1, unusually stout and mark-
edly sinuous rugulae lead to a unique pattern
not documented so far for any modern species.
Castaneoideae PT 2
Pl. 1, gs 10–12; Pl. 3, gs 13–15; Pl. 8, gs 1–15; Pl. 12,
gs 14–16
D e s c r i p t i o n. Pollen, monad, prolate, out-
line lobate in polar view, elliptic in equatorial
view; polar axis 13–20 µm long, equatorial dia-
meter 9–12 µm; tricolporate, colpi long, pori
lalongate, nexine slightly thickened around
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016 257
pori (LM); exine 0.7–0.9 µm thick (LM), nexine
thinner than sexine; tectate; sculpture psilate
in LM, rugulate, fossulate, perforate in SEM;
rugulae densely packed, irregularly arranged
or aligned, 130–320 nm wide, stout, sometimes
branching (bifurcating), rugulae and fossulae
less distinct in polar regions, rugulae fusing
along colpi and in central polar area (SEM).
L oca lit ie s/a ge. Elk Basin, Wyoming (82–81
Ma); Turritellakløft (Big section; Agatdalen),
western Greenland (64–62 Ma); Qeqertarsuat-
siaq, western Greenland (42–40 Ma; Grímsson
et al. 2015a, gs 8a–l).
R e m a r k s. Differs from Castaneoideae PT 4
and Castaneoideae PT 5 in size and form. Casta-
neoideae PT 2 can have much longer rugulae
than Castaneoideae PT 9; the rugulae are
generally broader, such as those in Castane-
oideae PT 4. Castaneoideae PT 2 differs from
Castaneoideae PT 4 also by more elongated
pori. Pollen grains of most extant Castaneoi-
deae species studied so far (Praglowski 1984;
comprising all ve genera) would fall within
Castaneoideae PT 2 as recognised here.
Castaneoideae PT 3
Pl. 9, gs 7–15
D e s c r i p t i o n. Pollen, monad, prolate to
spheroidal, outline lobate in polar view, ellip-
tic to circular in equatorial view; polar axis
8–11 µm long, equatorial diameter 5–10 µm;
tricolporate, colpi long, pori small (LM); exine
0.7–0.9 µm thick (LM), nexine thinner than
sexine; tectate; sculpture psilate in LM,
rugulate, fossulate, perforate in SEM; rugu-
lae densely packed, irregularly arranged or
aligned, 160–330 nm wide, stout, sometimes
branching (bifurcating), rugulae and fossulae
less distinct in polar regions, rugulae fusing
along colpi and in central polar area (SEM).
L o c a l i t y / a g e. Turritellakløft (Big section;
Agatdalen), western Greenland (64–62 Ma).
R e m ark s. This morphotype is very similar to
Castaneoideae PT 2, but the pollen grains are
much smaller and more spheroidal.
Castaneoideae PT 4 (aff. Lithocarpus)
Pl. 10, gs 1–15
D e s c r i p t i o n. Pollen, monad, prolate to
spheroidal, outline lobate in polar view, elliptic
in equatorial view; polar axis 14–17 µm long,
equatorial diameter 12–15 µm; tricolporate,
colpi long, pori circular (LM); exine 0.9–1.1 µm
thick (LM), nexine thinner than sexine; tectate;
sculpture psilate in LM, rugulate, fossulate,
perforate in SEM; rugulae densely packed,
irregularly arranged, 220–670 nm wide, stout,
branching (bifurcating), rugulae fusing along
colpi and in central polar area, running in par-
allel along colpi (SEM).
L o c a l i t y / a g e. Turritellakløft (Big section;
Agatdalen), western Greenland (64–62 Ma).
R e m a r k s. Differs from Castaneoideae PT 9
in size and form and in sculpture; Castaneoi-
deae PT 4 has much fewer and broader rugu-
lae. Castaneoideae PT 4 pollen has so far only
been found in members of the genus Lithocar-
pus (Praglowski 1984).
Castaneoideae PT 5
Pl. 11, gs 1–3
D e scr i pti o n. Pollen, monad, prolate, outline
lobate in polar view, elliptic in equatorial view;
polar axis 19–20 µm long, equatorial diameter
14–15 µm; tricolporate, colpi long, pori small
and lolongate, nexine slightly thickened around
pori (LM); exine 0.8–1.0 µm thick (LM), nexine
thinner than sexine; tectate; sculpture psilate
in LM, microrugulate to rugulate, fossulate,
perforate in SEM; rugulae densely packed,
irregularly arranged, 140–330 nm wide, stout,
sinuous and often bifurcating, equally devel-
oped across entire pollen grain (SEM).
L o c a l i t y / a g e. Turritellakløft (Big section;
Agatdalen), western Greenland (64–62 Ma).
R e m a r k s. Like Castaneoideae PT 2–4 and 6,
Castaneoideae PT 5 differs from Castaneo-
ideae PT 7–9 in being strictly rugulate with
thin/indistinct fossulae. This is a feature also
exhibited by all extant members of the Casta-
neoideae.
Castaneoideae PT 6
Pl. 11, gs 4–6
D e s c r i p t i o n. Pollen, monad, prolate, out-
line lobate in polar view, elliptic in equatorial
view; polar axis 17–18 µm long, equatorial
diameter 12–13 µm; tricolporate, colpi long,
pori small and lolongate, nexine slightly thick-
ened around pori (LM); exine 0.9–1.0 µm thick
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
258 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
(LM), nexine thinner than sexine; tectate;
sculpture psilate in LM, rugulate, fossulate,
perforate in SEM, rugulae elongated, 230–
410 nm wide, irregularly arranged or aligned,
sculpture prominently developed in polar and
equatorial regions.
L o c a l i t y / a g e. Turritellakløft (Big section;
Agatdalen), western Greenland (64–62 Ma).
R e m a r k s. This pollen type is similar to
Castaneoideae PT 2 but has lolongate pori,
is slightly broader, has wider sculpture ele-
ments, and the sculpture is also prominently
developed in the polar regions.
Castaneoideae PT 7
Pl. 11, gs 7–9
D e scr i pti o n. Pollen, monad, prolate, outline
lobate in polar view, elliptic in equatorial view;
polar axis 15–16 µm long, equatorial diameter
10–11 µm; tricolporate, colpi long, pori small
and lolongate, nexine slightly thickened around
pori (LM); exine 0.8–0.9 µm thick (LM), nexine
thinner than sexine; tectate; sculpture psilate
in LM, intermediate between rugulate, fossu-
late/highly perforate, and (micro)striato-retic-
ulate in SEM, fossulae composed of series of
perforations, rugulae/striae 160–330 nm wide,
sculpture prominently developed in polar and
equatorial regions.
L o c a l i t y / a g e. Turritellakløft (Big section;
Agatdalen), western Greenland (64–62 Ma).
R e m ark s. Castaneoideae PT 7–PT 9 are very
similar in LM. In SEM, Castaneoidea PT 7 is
structurally intermediate between Castaneoi-
dea PT 6 and Castaneoideae PT 8 and PT 9.
Castaneoideae PT 7–PT 9 differ from Casta-
neoideae PT 1–PT 5 by their partly (micro)
striato-reticulate sculpture, and in some case
also the outline of the pori.
Castaneoideae PT 8
Pl. 11, gs 10–12
D e scr i pti o n. Pollen, monad, prolate, outline
lobate in polar view, elliptic in equatorial view;
polar axis 18–19 µm long, equatorial diam-
eter 10–11 µm; tricolporate, colpi long, pori
small and lolongate, nexine slightly thickened
around pori (LM); exine 0.7–0.8 µm thick (LM),
nexine thinner than sexine; tectate; sculpture
psilate in LM, intermediate between rugulate,
highly perforate, partly fossulate, and (micro)
striato-reticulate in SEM, rugulae/striae 270–
450 nm wide, sculpture prominently developed
in polar and equatorial regions.
L o c a l i t y / a g e. Turritellakløft (Big section;
Agatdalen), western Greenland (64–62 Ma).
R e m a r k s. See remarks for Castaneoideae
PT 7.
Castaneoideae PT 9
Pl. 11, gs 13–15
D e s c r i p t i o n. Pollen, monad, prolate, out-
line lobate in polar view, elliptic in equatorial
view; polar axis 19–21 µm long, equatorial
diameter 10–11 µm; tricolporate, colpi long,
pori small (LM); exine 0.6–0.8 µm thick (LM),
nexine thinner than sexine; tectate; sculp-
ture psilate in LM, (micro)striato-reticulate in
SEM, striae/muri 200–500 nm wide, sculpture
prominently developed in polar and equatorial
regions, (micro)striato-reticulum fusing along
colpi (SEM).
L o c a l i t y / a g e. Turritellakløft (Big section;
Agatdalen), western Greenland (64–62 Ma).
R e m a r k s. A (micro)striate-reticulate sculp-
ture identical to that observed in the fossil
Castaneoidea PT 9 pollen has not been docu-
mented for any extant Castaneoideae species so
far. Overall, the pollen represents a more open
form of the typical Castaneoideae pollen, in
which the usually thin, often minute, rarer indi-
stinct fossulae are widened into small (< 1 µm
in diameter) lumina, particularly in the area of
the mesocolpium. This is a feature not seen in
any fossil and modern Castaneoideae studied so
far; thus, the Castaneoideae PT 9 may repre-
sent an extinct lineage of castaneoid Fagaceae.
Subfamily FAGOIDEAE K.Koch
Genus indet.
Fagoideae PT 1
Pl. 1, gs 13–15; Pl. 2, gs 1–16
D e s c r i p t i o n. Pollen, monad, oblate to sphe-
roidal, outline convex-triangular to circular
in polar view, circular to elliptic in equatorial
view; polar axis 14–24 µm long, equatorial
diameter 15–23 µm wide; tricolporate, colpi
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016 259
long to medium in length, pori elongated rec-
tangular (lalongate), nexine thickened around
pori (LM); exine markedly thick (1.3–1.8 µm),
nexine slightly thinner than sexine (LM); tec-
tate; sculpture scabrate in LM, rugulate, some
grains minutely fossulate in SEM, rugulae
short or long, up to 2.5 µm long, 230–360 nm
wide, usually sinuous, often multi-branched
and intertwined, tips of rugulae not protruding
(SEM).
L o c a l i t y / a g e. Elk Basin, Wyoming (82–
81 Ma).
R e m a r k s. This pollen type shows a consider-
able size range and arrangement of sculptural
elements seen under SEM. The sculpture can be
quite open (high relief), with the rugulae at dif-
ferent levels (Pl. 1, g. 15) as in modern Fagus,
or more closed, with the rugulae at the same
level separated by minute fossulae throughout
(Pl. 2, g. 3), a feature shared with Fagoideae
PT 2. The rugulae can be covered by sporopoll-
enin to a limited degree (Pl. 2, g. 14). Compara-
ble variation in sculpture has been observed in
pollen from the same modern or extinct species
(Denk 2003) and within the dispersed Fagus
pollen assemblages of Qeqertarsuatsiaq (middle
Eocene; Grímsson et al. 2015) and Lavanttal
(Grímsson et al. 2016a). Fagoideae PT 1 grains
differ from those of extinct and extant Fagus by
being smaller and the occurrence of elongated
rugulae, the tips of which are never protruding;
furthermore, rugulae in the Wyoming pollen
are often sinuous and multi-branched but usu-
ally straight (rod-like) and bifurcating in Fagus.
The pori in Fagus are mostly circular or lolon-
gate and rarely lalongate, but clearly lalongate
in these fossil pollen. The nexine thickening
around the pori is also more prominent than in
pollen of Fagus. A very conspicuous difference
between this pollen and extinct and extant pol-
len of Fagus is the conspicuously thick pollen
wall (nexine) encountered in the fossil pollen
(type 1 foot layer according to Denk & Tekleva
2014). Denk and Tekleva (2014) suggested
this to be a primitive, ancestral state in many
Fagaceae.
Fagoideae PT 2
Pl. 13, gs 1–3
D esc r ipt ion. Pollen, monad, prolate to sphe-
roidal, outline convex-triangular to circular in
polar view, elliptic to circular in equatorial
view; polar axis 26–27 µm long, equatorial
diameter 24–25 µm; tricolporate, colpi long,
pori elliptic (lolongate), nexine slightly thick-
ened around pori (LM); exine 1.4–1.6 µm thick
(LM), nexine thinner than sexine; tectate;
sculpture scabrate in LM, rugulate, minutely
fossulate in SEM, rugulae short (stout) to very
long (rod-like), up to 4.5 µm long, 400–500 nm
wide, straight or curved, occasionally bifurcat-
ing, tips of rugulae not protruding (SEM).
L o c a l i t y / a g e. Princeton Chert, British
Columbia (ca 48 Ma).
R e m a r k s. PT 2 differs from PT 1 in the form
and arrangement of sculpture elements. The
rugulae are often much longer in PT 2, bifur-
cating (not multi-branched), and are all occur-
ring in the same level. In LM the pollen mat-
ches that of Fagus (pollen size, wall thickness,
outline of pori). The thickening around the
pori is also similar to what can be observed in
Fagus. The very long rugulae and minute fos-
sulae are not characteristic of modern or fossil
Fagus, and the fossil pollen does not have the
protruding ends of rugulae observed in pollen
of all modern Fagus. The nexine most likely
corresponds to a weakly developed type 1 foot
layer, hence our treatment as Fagoideae PT.
Genus Fagus L.
Fagus PT 1
Pl. 3, gs 7–12
D e s c r i p t i o n. Pollen, monad, spheroidal,
outline convex-triangular in polar view, cir-
cular in equatorial view; polar axis 22–24 µm
long, equatorial diameter 21–25 µm; tricol-
porate, colpi long, pori circular, nexine thi-
ckened around pori (LM); exine 1.0–1.2 µm
thick, nexine thinner than sexine (LM); tec-
tate; sculpture scabrate in LM, microrugulate
in SEM, rugulae very short, 0.4–1.0 µm long,
220–320 nm wide, partly branched or fused
and protruding (SEM).
L o c a l i t y / a g e. Turritellakløft (Big section;
Agatdalen), western Greenland (64–62 Ma).
R e m a r k s. Pollen of the small genus Fagus
(ca nine species) has been studied comprehen-
sively using LM, SEM, and TEM (Praglowski
1982, Denk 2003). Pollen grains of extant Fagus
are generally similar in sculpture and outline
spheroidal). Pollen of species of ‘Subgenus
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
260 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
Engleriana’ according to Shen (1992), F. eng-
leriana, F. japonica, and F. okamotoi, with
a polar and equatorial axis ranging from 26
to 34 µm (Praglowski 1982, tab. 1; Denk 2003,
tab. 2), are typically smaller than those of
‘Subgenus Fagus’ (of Shen 1992), but still big-
ger than pollen from Agatdalen. The long colpi
seen in Fagus PT 1 are known from pollen of
‘Subgenus Engleriana’, but also F. grandifolia
(the only North American species) and occa-
sionally F. longipetiolata of ‘Subgenus Fagus’.
The oldest species of Fagus, F. langevinii
Manchester & Dillhoff (leaves, fruit, and pol-
len) known from the early Eocene of British
Columbia, western Canada, has very small to
small pollen grains with long colpi (Manches-
ter & Dillhoff 2004) very similar to the fos-
sil grains described here. In contrast, Fagus
pollen from the 20 Ma younger Hareøen Fm
is medium-large, and ts best with pollen of
F. grandifolia and F. longipetiolata (‘Subge-
nus Fagus’). The fossil record of Fagus (pollen,
cupules, nuts, leaves) has been summarised by
Manchester & Dillhoff (2004), Denk & Grimm
(2009a), and Grímsson et al. (2015). The Agat-
dalen pollen grains represent the oldest fossils
of Fagus currently known. The main distingu-
ishing feature between Fagoideae pollen clo-
sely resembling Fagus from the Cretaceous of
Wyoming and this pollen type is the derived
type 2 foot layer (see Denk & Tekleva 2014) in
the Paleocene pollen.
Fagus PT 2
Pl. 13, gs 4–6
D e s c r i p t i o n. Pollen, monad, spheroidal,
outline convex-triangular to circular in polar
view, circular in equatorial view; polar axis
22–23 µm long, equatorial diameter 21–22 µm;
tricolporate, colpi long, pori small, circular,
nexine slightly thickened around pori (LM);
exine 1.2–1.4 µm thick (LM), nexine thinner
than sexine; tectate; sculpture scabrate in LM,
microrugulate to rugulate, minutely fossulate
in SEM, rugulae short, 0.4–1.5 µm long, 180–
360 nm wide, straight or curved, bifurcations
rare, tips of rugulae can be protruding (SEM).
L o c a l i t y / a g e. Princeton Chert, British
Columbia (ca 48 Ma).
R e m a r k s. Regarding its sculpture, Fagus PT
2 is intermediate between Fagoideae PT 2 and
Fagus PT 3 from the same locality. Similarly
short, rarely unbranching microrugulae are
reminiscent of the sculpture of pollen included
in Fagoideae PT 1 from Wyoming (Pl. 2, g.
3), but it differs markedly in pollen shape and
porus outline. It is treated as Fagus because of
the occasionally protruding rugula tips and its
type 2 footlayer.
Fagus PT 3
Pl. 13, gs 7–10
D e s c r i p t i o n. Pollen, monad, spheroidal to
oblate, outline circular to convex-triangular
in polar view, circular in equatorial view;
polar axis 21–22 µm long, equatorial diameter
23–24 µm; tricolporate, colpi long, pori elliptic
(lolongate), nexine slightly thickened around
pori (LM); exine 1.0–1.3 µm thick (LM), nexine
thinner than sexine; tectate; sculpture scabrate
in LM, microrugulate in SEM, rugulae short,
rod-like, sometimes a bit curved, 0.3–1.1 µm
long, 200–300 nm wide, rarely branched, tips
of rugulae often protruding (SEM).
L o c a l i t y / a g e. Princeton Chert, British
Columbia (ca 48 Ma).
Re m ar k s. This pollen type shows all the diag-
nostic features of modern Fagus pollen observed
both in LM and SEM; it is only slightly smaller.
Like Fagus PT 1 it is most similar in size to pol-
len of ‘Subgenus Engleriana’, but also shares the
sculpture and colpi form/length with F. gran-
difolia. This pollen type differs from Fagus PT
1 in being more circular in polar view, having
lalongate pori and a less conspicuous thicken-
ing of the nexine around the pori. The rugulae
are longer and rarely fused.
Fagus cordifolia Heer (leaf morphotype 1)
Pl. 16, gs 1, 2
1883 Fagus cordifolia Heer – p. 83, pl. 92, g. 1.
D e s c r i p t i o n. Leaves, petiole not preserved,
lamina simple, 50 mm long, 32 mm wide,
length/width ratio 1.6, widest in the middle to
lower part of the lamina, lamina ovate, apex
bluntly acute, base slightly cordate, margin
crenulated to dentate, when present teeth
are simple and very small; primary venation
pinnate, primary vein moderate in thickness,
straight and becoming zigzag in apex region;
secondary venation pseudo- and semicraspe-
dodromous to craspedodromous, secondary
veins moderate in thickness, straight, 12 pairs
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016 261
diverging from midvein at intervals of 3 to
5 mm in middle of lamina, arising at angles
of 40° to 50° from midvein, usually alternate.
L o c a l i t y / a g e. Qeqertarsuatsiaq, western
Greenland (42–40 Ma).
R e m a r k s. This leaf resembles both Betula-
ceae and Fagaceae in having abmedial and/or
pectinal veins originating from the basalmost
secondary veins. While this is typical of Betu-
laceae, it is also seen in a number of extant
(‘Subgenus Engleriana’) and extinct species
(e.g. Fagus evenensis, F. pacica). The leaf
margin, pseudocraspedodromous to craspedo-
dromous, is typical of Fagus.
Fagus leaf morphotype 2
Pl. 16, gs 3–5; Pl. 17, gs. 1–5
D e s c r i p t i o n. Leaves, petiole not preserved,
lamina simple, up to 110 mm long (extrapo-
lated), 62 mm wide, length/width ratio 1.7–1.8,
widest in middle part of lamina, lamina ellip-
tic to wide elliptic, apex not preserved, base
obtuse, margin dentate, teeth simple and very
small, teeth with acute apex, basal side longer
than apical side, margin between two teeth
straight or sigmoid; primary venation pinnate,
primary vein moderate in thickness, straight;
secondary venation semicraspedodromous to
craspedodromous, secondary veins moderate
in thickness, straight to gently curved, 11 to
13 pairs (extrapolated) diverging from mid-
vein at intervals of 10 to 15 mm in middle of
lamina, arising at angles of 40° to 50° from
midvein, usually alternate above base; tertiary
venation percurrent, veins simple or branched,
convex, ca 5 tertiary veins per 1 cm secondary
vein, originating at acute angles from both the
admedial and the exmedial side of the second-
ary veins, alternately arranged; quaternary
venation orthogonal, forming large areoles;
areoles well developed, oriented, quadrangu-
lar to polygonal; veinlets branched; marginal
ultimate venation looped.
L o c a l i t y / a g e. Qeqertarsuatsiaq, western
Greenland (42–40 Ma).
Remarks. The Fagus LMT 2 leaves differ
from Fagus cordifolia in form of the lamina
and base. The teeth in Fagus LMT 2 are also
more prominent and more regular. Teeth are
rare in Fagus cordifolia. It is entirely possi-
ble that the few unambiguous leaves of Fagus
encountered from Qeqertarsuatsiaq were pro-
duced by the same species.
Subfamily QUERCOIDEAE Oerst.
Genus Quercus
Quercus PT 1
aff. Group Lobatae; Pl. 13, gs 11–13
D e s c r i p t i o n. Pollen, monad, prolate, out-
line lobate in polar view, elliptic in equatorial
view; polar axis 17–18 µm long, equatorial
diameter 13–14 µm; tricolporate, colpi long,
pori small (LM); exine 0.9–1.1 µm thick (LM),
nexine thinner or as thick as sexine; tectate;
sculpture scabrate in LM, (micro)verrucate,
fossulate, perforate in SEM, (micro)verrucae
with a microechinate suprasculpture, microe-
chini poorly developed, irregularly distributed
(SEM).
L o c a l i t i e s / a g e. Princeton Chert, Bri-
tish Columbia (ca 48 Ma); Qeqertarsuatsiaq,
western Greenland (42–40 Ma; Grímsson et al.
2015, g. 11)
Remarks. Quercus PT 1 falls within the
morphological variability of several species
of Quercus Group Lobatae of North America
(Solomon 1983a).
Quercus PT 2
(ancestral type with Group Ilex morphology)
Pl. 13, gs 14–19
D e scr i pti o n. Pollen, monad, prolate, outline
lobate in polar view, elliptic in equatorial view;
polar axis 17–24 µm long, equatorial diameter
12–14 µm; tricolporate, colpi long, pori small
(LM); exine 0.8–1.0 µm thick (LM), nexine
thinner than sexine; tectate; sculpture scab-
rate in LM, microrugulate, perforate in SEM,
rugulae short and narrow, 0.3–1.1 µm long,
100–200 nm wide, irregularly arranged (SEM).
L o c a l i t i e s / a g e. Princeton Chert, Bri-
tish Columbia (ca 48 Ma); Qeqertarsuatsiaq,
western Greenland (42–40; Grímsson et al.
2015, g. 14)
Remarks. Quercus PT 2 differs from other
PTs of Quercus, and pollen formalised here
as Paraquercus eocaena from the same local-
ity, by the lack of a verrucate suprasculpture
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
262 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
composed of conspicuously oriented or fused
(micro)rugulae. Among the modern species,
only the members of Quercus Group Ilex (and
Fagus) show unmasked, irregular-oriented
and intertwining rugulae, a situation that is
likely ancestral within genus Quercus (Denk
& Grimm 2009b). Further main distinguishing
features between the co-occurring Paraquercus
eocaena and Quercus PT 2 are the lalongate
endopori of Paraquercus, which are small to
indistinct in Quercus PT 2 as in other fossil
and extant pollen of genus Quercus. The rugu-
lae can be double as long in Quercus PT 2 com-
pared to Paraquercus eocaena. The ends of the
rugulae are frequently protruding from the
pollen surface (partly erect) in Quercus PT 2,
but never so in Paraquercus eocaena; the latter
can be observed in extant members of Quercus
Group Ilex (Denk & Tekleva 2014).
USING FAGACEAE POLLEN TO TRACE
ANCESTRAL, EXTINCT AND MODERN
(EXTANT) LINEAGES
The diagnostic value of pollen morphology
in Fagaceae at various hierarchical levels is
well and long established (Praglowski 1982,
1984, Solomon 1983a, b, Denk 2003, Denk
& Grimm 2009b). Figure 2 shows the position
of the here-described fossils against the back-
drop of the current evolutionary synopsis of
the family. Based on their stratigraphic distri-
bution and extant taxonomic sorting, the Cas-
taneoideae-type pollen appears to represent
the most ancestral morphology of Fagaceae
pollen, from which the other pollen types were
subsequently derived (Fagoideae, Eotrigono-
balanus/Paraquercus in the late Cretaceous;
Trigonobalanoideae, Trigonobalanopsis, Quer-
coideae in the Paleogene). The basic and most
common Castaneoideae pollen type (PT 2), still
found in extant Castaneoideae species (Pra-
glowski 1984, Wang & Pu 2004, Miyoshi et al.
2011) of genera that are more or less distantly
related (Chrysolepis + Lithocarpus; Castanea +
Castanopsis; Notholithocarpus, the genetically
closest relative of Quercus among the Cas-
taneoideae; Manos et al. 2008, Denk & Grimm
2010, Hubert et al. 2014) can be traced back to
the Campanian of Wyoming. One of the oldest
known Fagaceae, Archaefagacea from the early
Coniacian of Japan (Takahashi et al. 2008,
no LM micrograph shown), has a castaneoid
pollen with a sculpture equal to that of Cas-
taneoideae PT 2 (and PTs 3, 5, 6), whereas pol-
len of the slightly younger (Santonian) Anti-
quacupula (Sims et al. 1998) apparently has
a different sculpture. The pollen of Antiquacu-
pula is perforate and does not have the narrow
and oblong rugulae that are characteristic for
Castaneoideae-type pollen (see gs 13, 30–32
in Sims et al. 1998). Castaneoid pollen pre-
dates the so-far-known and here-reported rst
occurrences of Fagus (Fagoideae; Manchester
& Dillhoff 2004: 50 Ma; this study: 62–64 Ma)
and Quercus (Quercoideae; Hofmann 2010:
Paleocene-Eocene boundary, ca 55 Ma). Thus,
using pollen evidence, it is impossible to pin-
point the origin of modern (extant) genera of
the Castaneoideae.
INITIAL SPLIT INTO TWO MAIN CLADES
The rst split in the modern Fagaceae was
between a lineage leading to Fagus (Fagoi-
deae) and the rest of the family (trigonobala-
noids, Castaneoideae, Quercoideae). From
the branch-lengths in molecular phylograms
(Fig. 1) it is obvious that this split must have
happened long before the diversication of the
remainder of the family, which – based on fos-
sil evidence – was accomplished by the end of
the Eocene (Fig. 2). The Fagus/Fagoideae root
age, which is equivalent to the Fagaceae crown
age, is one of the few estimates unanimously
recovered by all dating approaches because of
the used constraints, which are densely packed
around the Fagaceae crown node. Independent
of the data set and approach used (node dating
or total evidence dating; Tab. 2), the estimates
range around ca 80 Ma (Campanian), ± 20 Ma
when the 95% condence intervals are consid-
ered (= Upper Cretaceous, 100.5–66 Ma; Cohen
et al. 2013, updated). Node dating (Sauquet
et al. 2012, Xiang et al. 2014, Xing et al. 2014)
infers minimum ages for most recent com-
mon ancestors (MRCA), hence, the molecular
estimates indicate that the Fagoideae lineage
was diverged by the middle Upper Cretaceous
(see File S2 for issues with the total evidence
dating used by Larson-Johnson 2016). This is
reected by the Campanian Fagaceae assem-
blage of Wyoming. In addition to two extinct
Fagaceae lineages of unknown relationship
to the modern two main clades (Eotrigonoba-
lanus, Paraquercus, discussed below), we nd
pollen showing diagnostic features shared with
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016 263
the later (Danian) and modern Fagus pollen,
in addition to sculptural elements reminis-
cent of the primitive (plesiomorphic) Castane-
oideae pollen from which it putatively evolved,
when the two main modern Fagaceae lineages
diverged (Fig. 3).
FAGUS CROWN AGE:
FORMATION OF MODERN LINEAGES
Miocene crown estimates (24–8 Ma) for
Fagus in the Fagales chronograms by Xiang
et al. (2014) and Xing et al. (2014) are too
young because the plastid data these studies
relied on (exclusively or partly) fail to capture
and resolve phylogenetic relationships in this
genus (details provided in File S2). Precur-
sors of all modern species/species complexes
were widespread already by the Miocene
(Denk 2004, Denk & Grimm 2009a). Species
of ‘Subgenus Engleriana’, a lineage that can
be traced back at least 15 Ma (Denk & Grimm
2009a), share highly similar to identical plas-
tid sequences with sympatric but distant rela-
tives of ‘Subgenus Fagus’ across their range,
in addition to unique haplotypes (Fujii et al.
2002, Zhang et al. 2013; see also Simeone et al.
2016a). For this reason, Renner et al. (2016)
used only two nuclear gene regions that are
able to infer sensible interspecies relation-
ships in Fagus (2nd intron of the LEAFY gene
and individual-consensus ITS sequences) for
Fig. 2. Plot of the Fagaceae fossils on a phylogenetic scheme (modied after Grímsson et al. 2015), which represents the syn-
opsis of undated and dated molecular phylogenies (Manos et al. 2008, Oh & Manos 2008, Denk & Grimm 2010, Hubert et al.
2014, Renner et al. 2016) and the fossil record. The age of the root node follows the consensus of all-Fagales-dated trees (Tab. 2)
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
264 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
their fossilised-birth-death (FBD) dating of the
genus. In contrast to node dating, where oldest
fossil(s) of a lineage are used to constrain mini-
mum root ages for that lineage, FBD dating
recruits the entire fossil record to inform the
temporal distribution of a lineage (Heath et al.
2014). For the FBD dating of Fagus more than
50 fossils informed the temporal distribution
of Fagus lineages (leading to the nine modern
species) and placed the divergence between
‘Subgenus Engleriana’ and ‘Subgenus Fagus’,
i.e. the Fagus crown age, into the Paleocene to
early Eocene (62–43 Ma; Tab. 2; Fig. 4). The
split between the North American (leading to
F. grandifolia) and Eurasian clades of ‘Subge-
nus Fagus’ (remainder of the genus; see also
Denk & Grimm 2009a) was estimated to be of
Eocene age (51–39 Ma). In line with these esti-
mates (Fig. 4), the Danian Fagus pollen shares
the long colpi seen in ‘Subgenus Engleriana’
and F. grandifolia, which apparently repre-
sents the ancestral situation in the genus.
A highly similar pollen has also been described
for the ca 50 Ma old F. langevinii (Manches-
ter & Dillhoff 2004), which so far has been the
earliest record of the genus and subsequently
has been used in recent node dating to con-
strain the Fagus root age (Fig. S1 in File S2).
Pollen with ancestral traits (small, long colpi)
are still present in the Princeton Chert beds.
On the other hand, the younger pollen grains
from Qeqertarsuatsiaq, western Greenland,
(42–40 Ma) match in size, form, and sculpture
that of modern members of ‘Subgenus Fagus’,
in striking agreement with the recent molecu-
lar dating (Fig. 4).
EVOLUTION AND RADIATION
OF THE CORE FAGACEAE
Although the primitive (plesiomorphic) Cas-
taneoideae pollen in general cannot be taken
as evidence for the presence of the modern
genera or their precursors, there are some sub-
types (Castaneoideae PT 4 and Castaneoideae
sp. 1 in Grímsson et al. 2015) which seem to be
restricted to a single extant genus (Lithocarpus
Fig. 3. Temporal distribution of early Fagaceae pollen. Grey bars show the general time range of pollen types covered in
this study; coloured discs reect the actual occurrence in one of the four studied localities. Six of these old pollen types (PT)
persist until today (Fagus, oaks [blue signatures], Castaneoideae basic type and Castanea-unique type); two (Trigonobalano-
psis, Eotrigonobalanus) went extinct throughout the Neogene (†); the remainder (Fagoideae PTs, extinct Castaneoideae PTs,
Paraquercus) have so far not been observed in younger time slices
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016 265
and Castanea, respectively). These could be
evidence that these genera (or the lineages
leading to them) were already established
in the Paleocene and Eocene. While plastid
data are highly ambiguous regarding interge-
neric relationships in the core Fagaceae (mod-
ern Castaneoideae + Quercus), nuclear data
(CRC, ITS) suggest a divergence scenario in
which Lithocarpus (+ Chrysolepis) was isolated
from the remainder (Quercus, Notholithocar-
pus, Castanea + Castanopsis) before Quercus
diversied, radiated, and separated from
the remaining Castaneoideae (Oh & Manos
2008, Denk & Grimm 2010). Such a scenario
would be in agreement with the pollen record
(Danian PT4 vs middle Eocene Castaneoideae
sp. 1). Relying exclusively or partly on plastid
data, all-Fagales dated trees failed to recog-
nise a single oak clade in studies using more
than a single accession to represent the oaks
(Xiang et al. 2014, Xing et al. 2014) and dif-
fer in the placement of Lithocarpus and the
other castaneoids (File S2). Nevertheless,
since these studies rely on the same fossil
priors to constrain the primary divergences in
the Fagaceae, and intergeneric relationships
within the core Fagaceae relate to very short
branches (Fig. 1), they all estimated a Paleo-
gene (Paleocene to Eocene) crown age for the
core Fagaceae (Tab. 2).
The lack of oak pollen in the Danian of
western Greenland, compared to signicant
diversity 20 Ma later in the same area, lends
further credibility to the hypothesis that oaks
evolved and started to radiate in the late Pale-
ocene/early Eocene, as estimated by Hubert
et al. (2014), i.e. more than 20 Ma earlier than
estimated by all-Fagales chronograms using
a single placeholder per genus (Tab. 2; Sau-
quet et al. 2012, Larson-Johnson 2016). Hubert
et al.’s (2014) preferred chronogram – which
used the oldest unambiguous record of Quercus
Group Cyclobalanopsis as minimum age con-
straint for the most recent common ances-
tor (MRCA) of the ‘Old World’ clade (Hubert
et al. 2014, g. 5) – points to an early Eocene
Quercus crown age; the latter is dened by the
divergence of the ‘New World’ or high-latitude
Fig. 4. Paleogene pollen records of Fagus compared to a recent dated tree of the genus inferred using fossilised-birth-death
(FBD) dating and a set of over 50 beech micro-, meso-, and macrofossils (modied from Renner et al. 2016). Fossil taxa included
for the FBD dating were placed along branches based on direct (as inferred; cf. Denk & Grimm 2009a) and indirect (personal
expertise; provenance) evidence. The stratigraphic position of newly found Fagus pollen is indicated
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
266 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
clade (Quercus Groups Lobatae, Protobalanus,
and Quercus) and the ‘Old World’ clade or mid-
latitude clade (Groups Cyclobalanopsis, Ilex,
and Cerris). Crown-group radiation within
the high-latitude clade of oaks, the divergence
between the red oak lineage (Group Lobatae)
and the golden cup-white oak lineage (Groups
Protobalanus, Quercus), was completed by the
middle Eocene. This is evidenced by pollen
found in the Princeton Chert (this study) and
on the island of Qeqertarsuatsiaq (Grímsson
et al. 2015), nds that are in good agreement
with Hubert et al.’s preferred chronogram
indicating an absolute minimum age (upper
boundary of the 95% condence interval)
for the MRCA of the high-latitude clade of
ca 35 Ma (i.e. Eocene-Oligocene boundary).
FAGOPSIPHYLLUM AND
PARAQUERCUS – OAK-LIKE FOLIAGE
AND OAK-LIKE POLLEN
BUT NOT OAKS
Grímsson et al. (2015) speculated that the
more primitive, extinct oak pollen types found
in the 42–40 Ma Hareøn Fm come from the
same plant/plant group that produced the
Fagopsiphyllum foliage (Pl. 6, 7; Pl. 14). Indeed,
there is a general similarity between Fagopsi-
phyllum and leaves of two modern, highly dis-
junct relict white oak species, Quercus pontica
from north-eastern Turkey and south-western
Georgia and Q. sadleriana from north-western
California, two relicts originating from an ini-
tial radiation within the high-latitude oak clade
(Hubert et al. 2014, Hipp et al. 2015; formal
publication is currently under preparation;
A. Hipp, pers. comm., 2016). The occurrence of
potentially ancestral oak-like foliage and pollen
types that show an ornamentation as would be
expected for an ancestral oak (Denk & Grimm
2009b) in the right time scale (cf. Hubert et al.
2014) is puzzling. However, the Wyoming pol-
len described here as Paraquercus campania is
much too old to be produced by an ancient oak
lineage and shows the same unique basic orna-
mentation as the pollen from the Hareøn Fm
that Grímsson et al. (2015) addressed as ‘Quer-
cus sp. 5’. For this reason, the latter is moved
to the new genus Paraquercus. Fagopsiphyllum
foliage is much more abundant in the Agatdal
Fm than in the younger Hareøen Fm (Heer
1868–1883). However, we found no evidence of
oak pollen in the older Agatdal Fm. The pres-
ervation of the foliage in both formations indi-
cates that the plants producing and shedding
the Fagopsiphyllum foliage lived close to the
depositional area; hence, it would be expected
that their pollen can also be found if the foli-
age comes from an oak, as oaks are strictly
wind-pollinated. Thus, the earlier ancient-
oak-hypothesis for Fagopsiphyllum must be
rejected. Three scenarios remain: (1) Fagopsi-
phyllum is the foliage from an extinct Fagales
member, not a Fagaceae, and producing non-
Fagaceae-like pollen grains; (2) Fagopsiphyl-
lum is the foliage from an extinct Fagaceae lin-
eage producing (very) few pollen grains, which
are not captured in the dispersed pollen record;
(3) Fagopsiphllyum is the foliage produced by
plants with Castaneoideae-like or Fagus-like
pollen. Scenario 1 is unlikely given the temporal
and spatial restriction of Fagopsiphyllum dur-
ing the Paleogene of the Arctic region, a time
and area renowned for a vegetation including
the earliest reliable records of deciduous, large-
leaved Fagaceae (Heer 1868, 1883, Manchester
& Dillhoff 2004, Dillhoff et al. 2005). If such
leaves evolved independently in other Fagales
lineages, they should be more common and
widespread in the fossil record and even per-
sisting in other extant families of the Fagales.
Scenario 2 remains possible. Analysing pollen
found in situ on fossil Eocene bees, Grímsson
et al. (2016c) recently showed that only a frac-
tion of insect-pollinated taxa can be retrieved
from the dispersed pollen record. The newly
recognised Paraquercus is notably rare in both
the Wyoming and Qeqertarsuatsiaq localities.
In both cases a single grain was found. Fago-
psiphyllum foliage has recently been described
from the latest Cretaceous of the Russian Far
East (Gnilovskaya & Golovneva 2016). So it
may be that the Paraquercus pollen and Fago-
psiphyllum leaves come from the same plant,
but the currently available association evidence
is weak. Hence, we prefer to coin a new genus
for the pollen. If scenario 3 applies, the common
Castaneoideae PT 2 would be the likeliest can-
didate for pollen of the Fagopsiphyllum plant,
as it is a type shared by several genetically dis-
tinct extant genera (species of Castanea-Cas-
tanopsis as well as Lithocarpus) and an early
Fagaceae, Archaeofagaceae (Takahashi et al.
2008), and has been found in both formations
(Tab. 2; Grímsson et al. 2015: “Castaneoideae
sp. 2”; this study).
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016 267
ACKNOWLEDGEMENTS
This work was supported by the Austrian Science
Fund, FWF, project numbers P24427-B25 (to FG) and
M1751-B16 (to GWG), and Synthesis FP7—the Euro-
pean Union–funded Integrated Activities Grants DK-
TAF 1971, SE-TAF 1918, and GB-TAF 3740 (to FG),
and by the Swedish Research Council (VR; grant to TD).
REFERENCES
ACOSTA M.C. & PREMOLI A.C. 2010. Evidence of
chloroplast capture in South American Nothofagus
(subgenus Nothofagus, Nothofagaceae). Mol. Phy-
logenet. Evol., 54: 235–242.
APG III 2009. An update of the Angiosperm Phylogeny
Group classication for the orders and families of
owering plants: APG III. Bot. J. Linn. Soc., 161:
105–121.
BOUCHAL J., ZETTER R., GRÍMSSON F. & DENK T.
2014. Evolutionary trends and ecological differenti-
ation in early Cenozoic Fagaceae of western North
America. Am. J. Bot., 101: 1332–1349.
BOULTER M.C. & KVAČEK Z. 1989. The Palaeocene
ora of the Isle of Mull. Palaeont. Assoc. London
Spec. Pap. Palaeont., 42: 1–149.
BROWN R.W. 1962. Paleocene oras of the Rocky
Mountains and Great Plains. U.S. Geol. Surv. Prof.
Paper, 375: 1–119.
COHEN K.M., FINNEY S., GIBBARD P.L. & FAN
J.-X. 2013, updated. The ICS international Chro-
nostratigraphic Chart. Episodes, 36: 199–204.
CREPET W.L. & NIXON K.C. 1989. Earliest megafos-
sil evidence of Fagaceae: phylogenetic and biogeo-
graphic implications. Am. J. Bot., 76: 842–855.
DENK T. 2003. Phylogeny of Fagus L. (Fagaceae)
based on morphological data. Plant Syst. Evol.,
240: 55–81.
DENK T. 2004. Revision of Fagus from the Cenozoic
of Europe and South Western Asia and its phyloge-
netic implications. Doc. Nat., 150: 1–72.
DENK T. & DILLHOFF R.M. 2005. Ulmus leaves and
fruits from the Early-Middle Eocene of northwest-
ern North America: Systematics and implications
of characters evolution within Ulmaceae. Can. J.
Bot., 83: 1663–1681.
DENK T. & GRIMM G.W. 2009a. The biogeographic
history of beech trees. Rev. Palaeobot. Palynol.,
158: 83–100.
DENK T. & GRIMM G.W. 2009b. Signicance of pol-
len characteristics for infrageneric classication
and phylogeny in Quercus (Fagaceae). Int. J. Plant
Sci., 170: 926–940.
DENK T. & GRIMM G.W. 2010. The oaks of western
Eurasia: traditional classications and evidence
from two nuclear markers. Taxon, 59: 351–366.
DENK T. & TEKLEVA M.V. 2014. Pollen morphology
and ultrastructure of Quercus with focus on Group
Ilex (= Quercus Subgenus Heterobalanus (Oerst.)
Menitsky): implications for oak systematics and
evolution. Grana, 53: 255–282.
DENK T., GRIMM G.W. & HEMLEBEN V. 2005. Pat-
terns of molecular and morphological differentia-
tion in Fagus: implications for phylogeny. Am. J.
Bot., 92: 1006–1016.
DENK T., GRÍMSSON F. & ZETTER R. 2012. Faga-
ceae from the early Oligocene of Central Europe:
persisting New World and emerging Old World
biogeographic links. Rev. Palaeobot. Palynol., 169:
7–20.
DENK T., GRÍMSSON F., ZETTER R. & SÍMONAR-
SON L.A. 2011. Late Cainozoic Floras of Iceland:
15 Million Years of Vegetation and Climate History
in the Northern North Atlantic. Topics in Geobiol-
ogy, vol. 35. Springer, Heidelberg, New York.
DILLHOFF R.M., LEOPOLD E.B. & MANCHESTER
S.R. 2005. The McAbee ora of British Columbia
and its relation to the early-middle Eocene Okana-
gan Highlands ora of the Pacic Northwest. Can.
J. Earth Sci., 42: 151–166.
ELLIS B., DALY D.C., HICKEY L.J., JOHNSON K.R.,
MITCHELL J.D., WILF P. & WING S.L. 2009.
Manual of Leaf Architecture. Cornell University
Press, New York.
FUJII N., TOMARU N., OKUYAMA K., KOIKE T.,
MIKAMI T. & UEDA K. 2002. Chloroplast DNA
phylogeography of Fagus crenata (Fagaceae) in
Japan. Plant Syst. Evol., 232: 21–33.
GNILOVSKAYA A.A. & GOLOVNEVA L.B. 2016.
Fagaceous foliage from the latest Cretaceous of
the Koryak Upland (northeastern Russia) and its
implications for the evolutionary history of the
Fagaceae. Rev. Palaeobot. Palynol., 228: 57–66.
GRIMM G.W. & DENK T. 2010. The reticulate origin
of modern plane trees (Platanus, Platanaceae) –
a nuclear marker puzzle. Taxon, 59: 134–147.
GRÍMSSONF., DENK T., ZETTER R. 2008. Pollen,
fruits, and leaves of Tetracentron (Trochodendra-
ceae) from the Cainozoic of Iceland and western
North America and their palaeobiogeographic
implications. Grana, 47: 1–14.
GRÍMSSON F., ZETTER R., BAAL C. 2011. Combined
LM and SEM study of the Middle Miocene (Sarma-
tian) palynoora from the Lavanttal Basin, Aus-
tria: Part I. Bryophyta, Lycopodiophyta, Pterido-
phyta, Ginkgophyta, and Gnetophyta. Grana, 50:
102–128.
GRÍMSSON F., GRIMM G.W., MELLER B., BOUCHAL
J.M. & ZETTER R. 2016a. Combined LM and SEM
study of the Middle Miocene (Sarmatian) palyno-
ora from the Lavanttal Basin, Austria: Part IV.
Magnoliophyta 2 – Fagales to Rosales. Grana, 55:
101–163.
GRÍMSSON F., PEDERSEN G.K., GRIMM G.W.,
ZETTER R. 2016b. A revised stratigraphy for the
Paleocene Agatdalen ora (Nuussuaq Peninsula,
western Greenland): correlating fossiliferous out-
crops, macrofossils and palynological samples from
phosphoritic nodules. Acta Palaeobot., 56(2): 307–327.
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
268 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
GRÍMSSON F., ZETTER R., LABANDEIRA C.C.,
ENGEL M.S. & WAPPLER T. 2016c. Taxo-
nomic description of in situ bee pollen from
the middle Eocene of Germany. Grana. DOI:
10.1080/00173134.2015.1108997.
GRÍMSSON F., ZETTER R., GRIMM G.W., PEDERSEN
G.K., PEDERSEN A.K. & DENK T. 2015. Fagaceae
pollen from the early Cenozoic of West Greenland:
revisiting Engler’s and Chaney’s Arcto-Tertiary
hypotheses. Plant Syst. Evol., 301: 809–832.
HARADA K., TAMAKI K., KAMIYA K. & TAKECHI Y.
2003. Pollen morphology observed by scanning
electron microscopy on Japanese Fagaceae species
and molecular phylogeny. Bull. Ehime Univ. For.,
42: 1–19.
HEATH T.A., HUELSENBECK J.P. & STADLER T.
2014. The fossilized birth–death process for coher-
ent calibration of divergence-time estimates. Proc.
Nat. Acad. Sci., 111: E2957–E2966.
HEENAN P.B. & SMISSEN R.D. 2013. Revised cir-
cumscription of Nothofagus and recognition of the
segregate genera Fuscospora, Lophozonia, and Tri-
syngyne (Nothofagaceae). Phytotaxa, 146: 1–31.
HEER O. 1868. Flora fossilis arctica 1. Die Fossile
Flora der Polarländer enthaltend die in Nordgrön-
land, auf der Melville-Insel, im Banksland, am
Mackenzie, in Island und in Spitzbergen entdeck-
ten fossilen Panzen. F. Schulthess, Zürich.
HEER O. 1868–1883. Flora Fossilis Arctica, vol. 1–7.
Kongliga Vetenskaps Akademiens Handlingar,
Stockholm.
HEER O. 1883. Flora fossilis arctica 7. Die fossile
Flora der Polarländer. Enthaltend: Den zweiten
Theil der fossilen Flora Grönlands. J. Wurster
& Comp., Zürich.
HESSE M., HALBRITTER H., ZETTER R., WEBER M.,
BUCHNER R., FROSCH-RADIVO A. & ULRICH
S. 2009. Pollen terminology – An illustrated hand-
book. Springer, Wien, New York.
HICKEY L.J. 1973. Classication of the architecture
of dicotyledonous leaves. Amer. J. Bot., 60: 17–33.
HICKS J.F. 1993. Chrono-stratigraphic analysis of the
foreland basin sediments of the latest Cretaceous,
Western Interior, U.S.A. Ph.D. Thesis. Yale Uni-
versity, New Haven, Connecticut.
HIPP A.L., EATON D.A.R., CAVENDER-BARES J.,
FITZEK E., NIPPER R. & MANOS P.S. 2014.
A framework phylogeny of the American oak clade
based on sequenced RAD data. PLoS ONE, 9:
e93975.
HIPP A.L., MANOS P., MCVAY J.D., CAVEN-
DER-BARES J., GONZÁLEZ-RODRIGUEZ A.,
ROMERO-SEVERSON J., HAHN M., BROWN
B.H., BUDAITIS B., DENG M., GRIMM G.,
FITZEK E., CRONN R., JENNINGS T.L., AVIS-
HAI M. & SIMEONE M.C. 2015. A phylogeny
of the World’s oaks. Botany 2015: http://2015.
botanyconference.org/engine/search/index.php?func
=detail&aid=1305.
HOFMANN C.-C. 2010. Microstructure of Fagaceae
pollen from Austria (Paleocene/Eocene boundary)
and Hainan Island (?middle Eocene). 8th European
Palaeobotany-Palynology Conference: 119.
HOFMANN C.-C. & ZETTER R. 2007. Upper Creta-
ceous pollen ora from the Vilui Basin, Siberia:
Circumpolar and endemic Aquilapollenites, Mani-
corpus, and Azonia. Grana, 46: 227–249.
HOFMANN C.-C. & ZETTER R. 2010. Upper Creta-
ceous sulcate pollen from the Timerdyakh Forma-
tion, Vilui Basin (Siberia). Grana, 49: 170–193.
HOFMANN C.-C., MOHAMED O. & EGGER H. 2011.
A new terrestrial palynoora from the Palaeocene/
Eocene boundary in the northwestern Tethyan
realm (St. Pankraz, Austria). Rev. Palaeobot. Paly-
nol., 166: 295–310.
HUBERT F., GRIMM G.W., JOUSSELIN E., BERRY V.,
FRANC A. & KREMER A. 2014. Multiple nuclear
genes stabilize the phylogenetic backbone of the
genus Quercus. Syst. Biodivers., 12: 405–423.
KANNO M., YOKOYAMA J., SUYAMA Y., OHYAMA
M., ITOH T. & SUZUKI M. 2004. Geographical dis-
tribution of two haplotypes of chloroplast DNA in
four oak species (Quercus) in Japan. J. Plant Res.,
117: 311–317.
KOCH B.E. 1963. Fossil plants from the lower Paleo-
cene of the Agatdalen (Angmârtussut) area, central
Nûgssuaq Peninsula, northwest Greenland. Medd.
Grønl. [Bull. Grønl. Geol. Unders.], 172[38]: 1–120.
KOHLMAN-ADAMSKA A. & ZIEMBIŃSKA-TWORZY-
DŁO M. 2000. Morphological variability and botani-
cal afnity of some species of the genus Tricolpo-
ropollenites Pf. et Thoms. from the Middle Miocene
Lignite association at Lubstów (Konin region – Cen-
tral Poland). Acta Palaeobot., 40: 49–71.
KVAČEK Z. & WALTHER H. 1988. Revision der mit-
teleuropäischen tertiären Fagaceen nach blattepi-
dermalen Charakteristiken II. Teil – Castanopsis
(D.Don) Spach, Trigonobalanopsis Kvaček & Wal-
ther. Feddes Repert., 99: 395–418.
KVAČEK Z. & WALTHER H. 1989. Palaeobotani-
cal studies in Fagaceae of the European Tertiary.
Plant Syst. Evol., 162: 213–229.
LARSEN L.M., PEDERSEN A.K., TEGNER C., DUN-
CAN R.A., HALD N. & LARSEN J.G. 2015. The
age of Tertiary volcanic rocks on the West Green-
land continental margin: volcanic evolution and
event correlation to other parts of the North Atlan-
tic Igneous Province. Geol. Mag., 153: 487–511.
LARSON-JOHNSON K. 2016. Phylogenetic investiga-
tion of the complex evolutionary history of disper-
sal mode and diversication rates across living and
fossil Fagales. New Phytol., 209: 418–435.
LI R.-Q., CHEN Z.-D., LU A.-M., SOLTIS D.E., SOLTIS
P.S. & MANOS P.S. 2004. Phylogenetic relation-
ships in Fagales based on DNA sequences from
three genomes. Int. J. Plant Sci., 165: 311–324.
MANCHESTER S.R. 1999. Biogeographical relation-
ships of North American Tertiary oras. Ann. Mis-
souri Bot. Gard., 86: 472–522.
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016 269
MANCHESTER S.R. & CRANE P.R. 1983. Attached
leaves, inorescences, and fruits of Fagopsis, an
extinct genus of fagaceous afnity from the Oli-
gocene Florissant ora of Colorado, U.S.A. Am. J.
Bot., 70: 1147–1164.
MANCHESTER S.R. & DILLHOFF R.M. 2004. Fagus
(Fagaceae) fruits, foliage, and pollen from the Mid-
dle Eocene of Pacic Northwestern North America.
Can. J. Bot., 82: 1509–1517.
MANCHESTER S.R., GRÍMSSON F. & ZETTER R.
2015. Assessing the fossil record of asterids in the
context of our current phylogenetic framework.
Ann. Missouri Bot. Gard., 100: 329–363.
MANOS P.S., ZHOU Z.K. & CANNON C.H. 2001.
Systematics of Fagaceae: Phylogenetic tests of
reproductive trait evolution. Int. J. Plant Sci., 162:
1361–1379.
MANOS P.S., CANNON C.H. & OH S.-H. 2008. Phy-
logenetic relationships and taxonomic status of the
paleoendemic Fagaceae of Western North Ame-
rica: recognition of a new genus, Notholithocarpus.
Madroño 55: 181–190.
MELLER B., KOVAR-EDER J. & ZETTER R. 1999.
Lower Miocene diaspore, leaf and palynomorph
assemblages from the base of the lignite-bear-
ing sequence in the opencast mine Oberdorf, N
Voitsberg (Styria, Austria) as an indication of
a “Younger Mastixioid” vegetation. Palaeontogr. B,
252: 123–179.
MIYOSHI N., FUJIKI T. & KIMURA H. 2011. Pollen
Flora of Japan. Hokkaido University Press, Sap-
poro.
MOSS P.T., GREENWOOD D.R. & ARCHIBALD
S.B. 2005. Regional and local vegetation commu-
nity dynamics of the Eocene Okanagan Highlands
(British Columbia – Washington State) from paly-
nology. Can. J. Earth Sci., 42: 187–204.
MUSTOE G.E. 2011. Cyclic sedimentation in the
Eocene Allenby Formation of south-central British
Columbia and the origin of the Princeton Chert fos-
sil beds. Can. J. Earth Sci., 48: 25–43.
NEOPHYTOU C., DOUNAVI A., FINK S. & ARA-
VANOPOULOS F.A. 2010. Interfertile oaks in an
island environment: I. High nuclear genetic differ-
entiation and high degree of chloroplast DNA shar-
ing between Q. alnifolia and Q. coccifera in Cyprus.
A multipopulation study. Eur. J. Forest Res., 130:
543–555.
NIXON K.C. & CREPET W.L. 1989. Trigonobalanus
(Fagaceae): taxonomic status and phylogenetic
relationships. Am. J. Bot., 76: 828–841.
OH S.-H. & MANOS P.S. 2008. Molecular phylogenet-
ics and cupule evolution in Fagaceae as inferred
from nuclear CRABS CLAW sequences. Taxon, 57:
434–451.
PALAMAREV E. & MAI D.H. 1998. Die paläogenen
Fagaceae in Europa: Artenvielfalt und Leitlinien
ihrer Entwicklungsgeschichte. Acta Palaeobot., 38:
227–299.
PRAGLOWSKI J. 1982. Fagaceae L. Fagoideae. World
Pollen and Spore Flora, 11: 1–28.
PRAGLOWSKI J. 1984. Fagaceae Dumort. Castaneoi-
deae Oerst. World Pollen and Spore Flora, 13: 1–21.
PREMOLI A.C., MATHIASEN P., ACOSTA M.C.
& RAMOS V.A. 2012. Phylogeographically con-
cordant chloroplast DNA divergence in sympatric
Nothofagus s.s. How deep can it be? New Phytol.,
193: 261–275.
PUNT W., HOEN P., BLACKMORE S. & LE THOMAS
A. 2007. Glossary of pollen and spore terminology.
Rev. Palaeobot. Palynol., 143: 1–81.
READ P.B. 2000. Geology and industrial minerals of
the Tertiary basins, British Columbia. GeoFiles:
110.
RENNER S.S., GRIMM G.W., KAPLI P. & DENK T.
2016. Species relationships and divergence times
in beeches: New insights from the inclusion of 53
young and old fossils in a birth-death clock model.
Phil. Trans. Roy. Soc. B., 371: 20150135.
SAUQUET H., HO S.Y., GANDOLFO M.A., JORDAN
G.J., WILF P., CANTRILL D.J., BAYLY M.J.,
BROMHAM L., BROWN G.K., CARPENTER R.J.,
LEE D.M., MURPHY D.J., SNIDERMAN J.M.
& UDOVICIC F. 2012. Testing the impact of cali-
bration on molecular divergence times using a fos-
sil-rich group: the case of Nothofagus (Fagales).
Syst. Biol., 61: 289–313.
SHEN C.F. 1992. A monograph of the genus Fagus
Thurn. ex L. (Fagaceae). Ph. D. Thesis. City Uni-
versity of New York, New York.
SIMEONE M.C., PIREDDA R., PAPINI A., VES-
SELLA F. & SCHIRONE B. 2013. Application of
plastid and nuclear markers to DNA barcoding of
Euro–Mediterranean oaks (Quercus, Fagaceae):
problems, prospects and phylogenetic implications.
Bot. J. Linn. Soc.: 478–499.
SIMEONE M.C., GRIMM G.W., PAPINI A., VES-
SELLA F., CARDONI S., TORDONI E., PIREDDA
R., FRANC A. & DENK T. 2016a. Plastome diver-
gence in Fagales. Supplemental information to:
Simeone et al., Plastome data reveal multiple geo-
graphic origins of Quercus Group Ilex. PeerJ. DOI:
10.7717/peerj.1897/supp-2.
SIMEONE M.C., GRIMM G.W., PAPINI A., VES-
SELLA F., CARDONI S., TORDONI E.,
PIREDDA R., FRANC A. & DENK T. 2016b.
Plastome data reveal multiple geographic ori-
gins of Quercus Group Ilex. PeerJ, 4: e1897. DOI:
10.7717/peerj.1897.
SIMS H.J., HERENDEEN P.S. & CRANE P.R. 1998.
New genus of fossil Fagaceae from the Santonian
(Late Cretaceous) of Central Georgia, U.S.A. Int. J.
Plant Sci., 159: 391–404.
SMITH S.Y. & STOCKEY R.A. 2007. Establish-
ing a fossil record for the perianthless Piperales:
Saururus tuckerae sp. nov. (Saururaceae) from the
Middle Eocene Princeton Chert. Am. J. Bot., 94:
1643–1657.
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
270 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
SOLOMON A.M. 1983a. Pollen morphology and plant
taxonomy of red oaks in eastern North America.
Am. J. Bot., 70: 495–507.
SOLOMON A.M. 1983b. Pollen morphology and plant
taxonomy of white oaks in eastern North America.
Am. J. Bot., 70: 481–492.
STEVENS P.F. 2001 onwards. Angiosperm Phylog-
eny Website. Version 8, June 2007 [and more or
less continuously updated since]. Available from:
http://www.mobot.org/MOBOT/research/APweb/.
Accessed 19/07/2014.
STUCHLIK L., ZIEMBÍNSKA-TWORZYDŁO M.
& KOHLMAN-ADAMSKA A. 2007. Botanical afn-
ity of some Neogene sporomorphs and nomencla-
tural problems. Acta Palaeobot., 47: 291–311.
TAKAHASHI M., FRIIS E.M., HERENDEEN P.S.
& CRANE P.R. 2008. Fossil owers of Fagales from
the Kamikitaba locality (Early Coniacian; Late
Cretaceous) of Northeastern Japan. Int. J. Plant
Sci., 169: 899–907.
VAN BOSKIRK M.C. 1998. The ora of the Eagle
Formation and its signicance for Late Cretaceous
oristic evolution. Ph.D. Thesis. Yale University,
New Haven, Connecticut.
VELITZELOS D., BOUCHAL J.M. & DENK T. 2014.
Review of the Cenozoic oras and vegetation of
Greece. Rev. Palaeobot. Palynol., 204: 56–117.
DOI: 10.1016/j.revpalbo.2014.02.006.
WALTHER H. & ZETTER R. 1993. Zur Entwicklung
der paläogenen Fagaceae Mitteleuropas. Palaeon-
togr. B, 230: 183–194.
WANG P.-L. & CHANG K.-T. 1988. On the pollen mor-
phology and systematic position of Trigonobalanus
doichangensis. Acta Phytotax. Sin., 26: 44–46.
WANG P.-L., PU F.-T. & ZHENG Z.-H. 1998. Paly-
nological evidence for taxonomy of Trigonobalanus
(Fagaceae). Acta Phytotax. Sin., 36: 238–241.
WANG P. & PU F. 2004. Pollen morphology and bio-
geography of Fagaceae. Guangdong Science and
Technology Press, Guangzhou.
XIANG X.-G., WANG W., LI R.-Q., LIN L., LIU Y.,
ZHOU Z.-K., LI Z.-Y. & CHEN Z.-D. 2014. Large-
scale phylogenetic analyses reveal fagalean diver-
sication promoted by the interplay of diaspores
and environments in the Paleogene. Perspect.
Plant Ecol. Evol. Syst., 16: 101–110.
XING Y., ONSTEIN R.E., CARTER R.J., STADLER T.
& LINDER H.P. 2014. Fossils and large molecu-
lar phylogeny show that the evolution of species
richness, generic diversity, and turnover rates are
disconnected. Evolution, 68: 2821–2832.
ZETTER R. 1989. Methodik und Bedeutung einer rou-
tinemäßig kombinierten lichtmikroskopischen und
rasterelektonenmikroskopischen Untersuchung fos-
siler Mikrooren. Cour. Forschungsinst. Sencken-
berg, 109: 41–50.
ZHANG Z.Y., WU R., WANG Q., ZHANG Z.R., LOPEZ-
PUJOL J., FAN D.M. & LI D.Z. 2013. Comparative
phylogeography of two sympatric beeches in sub-
tropical China: Species-specic geographic mosaic
of lineages. Ecology and Evolution, 3: 4461–4472.
DOI: Doi 10.1002/Ece3.829.
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
PLATES
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
272 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
Plate 1
Fagaceae pollen grains from the Cretaceous Eagle Formation, Elk Basin, Wyoming, USA
1. Paraquercus campania, LM equatorial view. Holotype, IPUW 7513/161. Scale bar: 10 µm
2. Paraquercus campania, SEM equatorial view, same grain as in 1. Holotype, IPUW 7513/161. Scale bar: 1 µm
3. Paraquercus campania, SEM, close-up of 2, showing parallel to radially arranged (micro)rugulae in groups.
Holotype, IPUW 7513/161. Scale bar: 1 µm
4. Eotrigonobalanus PT, LM equatorial view. IPUW 7513/162. Scale bar: 10 µm
5. Eotrigonobalanus PT, SEM equatorial view, same grain as in 4. IPUW 7513/162. Scale bar: 1 µm
6. Eotrigonobalanus PT, SEM, close-up of 5, showing twisted and interwoven microrugulae. IPUW 7513/162.
Scale bar: 1 µm
7. Castaneoideae PT 1, LM equatorial view. IPUW 7513/163. Scale bar: 10 µm
8. Castaneoideae PT 1, SEM equatorial view, same grain as in 7. IPUW 7513/163. Scale bar: 1 µm
9. Castaneoideae PT 1, SEM, close-up of 8, showing rugulate, fossulate, perforate sculpture. IPUW 7513/163.
Scale bar: 1 µm
10. Castaneoideae PT 2, LM equatorial view. IPUW 7513/164. Scale bar: 10 µm
11. Castaneoideae PT 2, SEM equatorial view, same grain as in 10. IPUW 7513/164. Scale bar: 1 µm
12. Castaneoideae PT 2, SEM, close-up of 11, showing rugulate, fossulate, perforate sculpture. IPUW 7513/164.
Scale bar: 1 µm
13. Fagoideae PT 1, LM equatorial view. IPUW 7513/165. Scale bar: 10 µm
14. Fagoideae PT 1, SEM polar view, same grain as in 13. IPUW 7513/165. Scale bar: 1 µm
15. Fagoideae PT 1, SEM, close-up of 14, showing sinuous, multi-branched and intertwined rugulae.
IPUW 7513/165. Scale bar: 1 µm
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
F. Grímsson et al.
Acta Palaeobot. 56(2)
Plate 1 273
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
274 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
Plate 2
Fagaceae pollen grains from the Cretaceous Eagle Formation, Elk Basin, Wyoming, USA
1. Fagoideae PT 1, LM equatorial view. IPUW 7513/166. Scale bar: 10 µm
2. Fagoideae PT 1, SEM polar view, same grain as in 1. IPUW 7513/166. Scale bar: 1 µm
3. Fagoideae PT 1, SEM, close-up of 2, showing sinuous and multi-branched rugulae. IPUW 7513/166.
Scale bar: 1 µm
4. Fagoideae PT 1, LM equatorial view (upper), polar view (lower). IPUW 7513/167. Scale bar: 10 µm
5. Fagoideae PT 1, SEM polar view, same grain as in 4. IPUW 7513/167. Scale bar: 1 µm
6. Fagoideae PT 1, SEM, close-up of 5, showing sinuous and multi-branched rugulae. IPUW 7513/167. Scale bar: 1 µm
7. Fagoideae PT 1, LM equatorial view. IPUW 7513/168. Scale bar: 10 µm
8. Fagoideae PT 1, SEM equatorial view, same grain as in 7. IPUW 7513/168. Scale bar: 10 µm
9. Fagoideae PT 1, SEM, close-up of 8, showing sculpture along colpi. IPUW 7513/168. Scale bar: 1 µm
10. Fagoideae PT 1, LM equatorial view (upper), polar view (lower). IPUW 7513/169. Scale bar: 10 µm
11. Fagoideae PT 1, SEM equatorial view, same grain as in 10. IPUW 7513/169. Scale bar: 1 µm
12. Fagoideae PT 1, SEM, close-up of 11, showing sculpture along colpi. IPUW 7513/169. Scale bar: 1 µm
13. Fagoideae PT 1, SEM equatorial view. IPUW 7513/170. Scale bar: 1 µm
14. Fagoideae PT 1, SEM, close-up of 13, showing sculpture partly obscured by sporopollenin. IPUW 7513/170.
Scale bar: 1 µm
15. Fagoideae PT 1, SEM polar view. IPUW 7513/171. Scale bar: 1 µm
16. Fagoideae PT 1, SEM, close-up of 15, showing sculpture in polar area. IPUW 7513/171. Scale bar: 1 µm
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
F. Grímsson et al.
Acta Palaeobot. 56(2)
Plate 2 275
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
276 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
Plate 3
Fagaceae pollen grains from the Paleocene Agatdal Formation, Turritellakløft (Big section) locality,
Agatdalen valley, western Greenland
1. Eotrigonobalanus PT, LM equatorial view (upper) and polar view (lower). IPUW 7513/172. Scale bar: 10 µm
2. Eotrigonobalanus PT, SEM equatorial view, same grain as in 1. IPUW 7513/172. Scale bar: 10 µm
3. Eotrigonobalanus PT, SEM, close-up of 2, showing rugulate and perforate sculpture, rugulae twisted and
interwoven. IPUW 7513/172. Scale bar: 1 µm
4. Eotrigonobalanus PT, LM equatorial view (upper) and polar view (lower). IPUW 7513/173. Scale bar: 10 µm
5. Eotrigonobalanus PT, SEM equatorial view, same grain as in 4. IPUW 7513/173. Scale bar: 10 µm
6. Eotrigonobalanus PT, SEM, close-up of 5, showing rugulate and perforate sculpture, rugulae twisted and
interwoven. IPUW 7513/173. Scale bar: 1 µm
7. Fagus PT 1, LM equatorial view (upper) and polar view (lower). IPUW 7513/174. Scale bar: 10 µm
8. Fagus PT 1, SEM oblique polar view, same grain as in 7. IPUW 7513/174. Scale bar: 10 µm
9. Fagus PT 1, SEM, close-up of 8, showing rugulate sculpture, rugulae sometimes clustered and often diverg-
ing and protruding. IPUW 7513/174. Scale bar: 1 µm
10. Fagus PT 1, LM equatorial view (upper) and polar view (lower). IPUW 7513/175. Scale bar: 10 µm
11. Fagus PT 1, SEM oblique equatorial view, same grain as in 10. IPUW 7513/175. Scale bar: 1 µm
12. Fagus PT 1, SEM, close-up of 11, showing rugulate sculpture, rugulae sometimes clustered and often diver-
ging and protruding. IPUW 7513/175. Scale bar: 1 µm
13. Castaneoideae PT 2, LM equatorial view (upper) and polar view (lower). IPUW 7513/176. Scale bar: 10 µm
14. Castaneoideae PT 2, SEM equatorial view, same gain as in 13. IPUW 7513/176. Scale bar: 1 µm
15. Castaneoideae PT 2, SEM, close-up of 14, showing rugulate sculpture, rugulae long. IPUW 7513/176.
Scale bar: 1 µm
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
F. Grímsson et al.
Acta Palaeobot. 56(2)
Plate 3 277
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
278 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
Plate 4
Fagaceae leaves from the Paleocene of Agatdalen, western Greenland
1. Eotrigonobalanus leaf morphotype, with decurrent base and petiole preserved, MGUH 10385. Agatkløft,
Agatdal Fm. Scale bar: 1 cm
2. Eotrigonobalanus leaf morphotype, base missing, MGUH 10384. Agatkløft, Agatdal Fm. Scale bar: 1 cm
3. Eotrigonobalanus leaf morphotype, complete lamina, petiole missing, MGUH 10383. Agatkløft, Agatdal Fm.
Scale bar: 1 cm
4. Eotrigonobalanus leaf morphotype, counterpart to 3, MGUH 10383. Agatkløft, Agatdal Fm. Scale bar: 1 cm
5. Eotrigonobalanus leaf morphotype, complete lamina, petiole missing, MGUH 10386. Agatkløft, Agatdal Fm.
Scale bar: 1 cm
6. Eotrigonobalanus leaf morphotype, lamina with few small teeth, MGUH 10462. Qaarsutjægerdal (Big section),
Agatdal Fm. Scale bar: 1 cm
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
F. Grímsson et al.
Acta Palaeobot. 56(2)
Plate 4 279
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
280 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
Plate 5
Fagaceae leaves from the Paleocene of Agatdalen, western Greenland
1. Eotrigonobalanus leaf morphotype, narrow lamina, MGUH 10376. Qaarsutjægerdal (Big section), Agatdal
Fm. Scale bar: 1 cm
2. Eotrigonobalanus leaf morphotype, narrow lamina, base missing, MGUH 10379. Agatkløft, Agatdal Fm
Scale bar: 1 cm
3. Eotrigonobalanus leaf morphotype, lower half of lamina with entire margin, MGUH 10380. Agatkløft, Agat-
dal Fm. Scale bar: 1 cm
4. Eotrigonobalanus leaf morphotype, teeth in upper third of lamina, MGUH 10377. Agatkløft, Agatdal Fm.
Scale bar: 1 cm
5. Eotrigonobalanus leaf morphotype, short elliptic lamina, MGUH 10461. Kangersooq (Quleruarsuup isua),
Agatdal Fm or Eqalulik Fm. Scale bar: 1 cm
6. Eotrigonobalanus leaf morphotype, close-up of counterpart to 1, showing secondary venation and teeth in
central part of lamina, MGUH 10376. Qaarsutjægerdal (Big section), Agatdal Fm. Scale bar: 1 cm
7. Eotrigonobalanus leaf morphotype, close-up of 2, showing secondary venation and marginal features, MGUH
10379. Agatkløft, Agatdal Fm. Scale bar: 1 cm
8. Eotrigonobalanus leaf morphotype, close-up of Pl. 4, g. 3, showing apex and teeth in apical region, MGUH
10383. Agatkløft, Agatdal Fm. Scale bar: 1 cm
9. Eotrigonobalanus leaf morphotype, close-up of Pl. 4, g. 2, showing teeth in upper part of lamina, MGUH
10384. Agatkløft, Agatdal Fm. Scale bar: 1 cm
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
F. Grímsson et al.
Acta Palaeobot. 56(2)
Plate 5 281
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
282 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
Plate 6
Fagaceae leaves from the Paleocene of Agatdalen, western Greenland
1. Fagopsiphyllum groenlandicum, small elliptic lamina, MGUH 10369. Kangersooq (Quleruarsuup isua), Agat-
dal Fm or Eqalulik Fm. Scale bar: 1 cm
2. Fagopsiphyllum groenlandicum, showing zig-zag central vein in apical region, counterpart to 1, MGUH
10369. Kangersooq (Quleruarsuup isua), Agatdal Fm or Eqalulik Fm. Scale bar: 1 cm
3. Fagopsiphyllum groenlandicum, medium sized elliptic lamina, central vein curved, MGUH 10372. Kanger-
sooq (Quleruarsuup isua), Agatdal Fm or Eqalulik Fm. Scale bar: 1 cm.
4. Fagopsiphyllum groenlandicum, part of large lamina, MGUH 10370. Kangersooq (Quleruarsuup isua), Agat-
dal Fm or Eqalulik Fm. Scale bar: 1 cm
5. Fagopsiphyllum groenlandicum, lower half of large lamina, MGUH 10371. Kangersooq (Quleruarsuup isua),
Agatdal Fm or Eqalulik Fm. Scale bar: 1 cm
6. Fagopsiphyllum groenlandicum, base form and venation, MGUH 10411. Kangersooq (Quleruarsuup isua),
Agatdal Fm or Eqalulik Fm. Scale bar: 1 cm
7. Fagopsiphyllum groenlandicum, base form and venation, MGUH 10437. Kangersooq (Quleruarsuup isua),
Agatdal Fm or Eqalulik Fm. Scale bar: 1 cm
8. Fagopsiphyllum groenlandicum, tertiary venation, MGUH 10411. Kangersooq (Quleruarsuup isua), Agatdal
Fm or Eqalulik Fm. Scale bar: 1 cm
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
F. Grímsson et al.
Acta Palaeobot. 56(2)
Plate 6 283
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
284 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
Plate 7
Fagaceae leaves from the Paleocene of Agatdalen, western Greenland
1. Fagopsiphyllum groenlandicum, close-up of Pl. 6, g. 3, showing basal part, MGUH 10372. Kangersooq
(Quleruarsuup isua), Agatdal Fm or Eqalulik Fm. Scale bar: 1 cm
2. Fagopsiphyllum groenlandicum, close-up of Pl. 6, g. 3, showing secondary veins ending in teeth, central
vein zig-zag in apical part, MGUH 10372. Kangersooq (Quleruarsuup isua), Agatdal Fm or Eqalulik Fm.
Scale bar: 1 cm
3. Fagopsiphyllum groenlandicum, close-up of 8, showing secondary veins ending in central part of tooth apex,
MGUH 10411. Kangersooq (Quleruarsuup isua), Agatdal Fm or Eqalulik Fm. Scale bar: 1 cm
4. Fagopsiphyllum groenlandicum, lower to middle part of lamina, petiole preserved, MGUH 10373. Kangersooq
(Quleruarsuup isua), Agatdal Fm or Eqalulik Fm. Scale bar: 1 cm
5. Fagopsiphyllum groenlandicum, lower part of big broadly based leaf, MGUH 10374. Kangersooq (Quleruar-
suup isua), Agatdal Fm or Eqalulik Fm. Scale bar: 1 cm
6. Fagopsiphyllum groenlandicum, upper lateral section of lamina, MGUH 10375. Kangersooq (Quleruarsuup
isua), Agatdal Fm or Eqalulik Fm. Scale bar: 1 cm
7. Fagopsiphyllum groenlandicum, part of elliptic lamina, numerous secondary veins, MGUH 10428. Kanger-
sooq (Quleruarsuup isua), Agatdal Fm or Eqalulik Fm. Scale bar: 1 cm
8. Fagopsiphyllum groenlandicum, part of large lamina, MGUH 10411. Kangersooq (Quleruarsuup isua), Agat-
dal Fm or Eqalulik Fm. Scale bar: 1 cm
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
F. Grímsson et al.
Acta Palaeobot. 56(2)
Plate 7 285
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
286 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
Plate 8
Fagaceae pollen grains from the Paleocene Agatdal Formation, Turritellakløft (Big section) locality,
Agatdalen valley, western Greenland
1. Castaneoideae PT 2, LM equatorial view. IPUW 7513/177. Scale bar: 10 µm
2. Castaneoideae PT 2, SEM equatorial view, same grain as in 1. IPUW 7513/177. Scale bar: 1 µm
3. Castaneoideae PT 2, SEM close-up of 2 showing rugulate, fossulate, perforate sculpture. IPUW 7513/177.
Scale bar: 1 µm
4. Castaneoideae PT 2, LM equatorial view (upper) and polar view (lower). IPUW 7513/178. Scale bar: 10 µm
5. Castaneoideae PT 2, SEM equatorial view, same grain as in 4. IPUW 7513/178. Scale bar: 1 µm
6. Castaneoideae PT 2, SEM, close-up of 5 showing rugulate, fossulate, perforate sculpture. IPUW 7513/178.
Scale bar: 1 µm
7. Castaneoideae PT 2, LM equatorial view (upper) and polar view (lower). IPUW 7513/179. Scale bar: 10 µm
8. Castaneoideae PT 2, SEM equatorial view, same grain as in 7. IPUW 7513/179. Scale bar: 1 µm
9. Castaneoideae PT 2, SEM, close-up of 8 showing rugulate, fossulate, perforate sculpture. IPUW 7513/179.
Scale bar: 1 µm
10. Castaneoideae PT 2, LM equatorial view. IPUW 7513/180. Scale bar: 10 µm
11. Castaneoideae PT 2, SEM equatorial view, same grain as in 10. IPUW 7513/180. Scale bar: 1 µm
12. Castaneoideae PT 2, SEM, close-up of 11 showing rugulate, fossulate, perforate sculpture. IPUW 7513/180.
Scale bar: 1 µm.
13. Castaneoideae PT 2, LM equatorial view. IPUW 7513/181. Scale bar: 10 µm
14. Castaneoideae PT 2, SEM equatorial view, same grain as in 13. IPUW 7513/181. Scale bar: 1 µm
15. Castaneoideae PT 2, SEM, close-up of 14 showing rugulate, fossulate, perforate sculpture. IPUW 7513/181.
Scale bar: 1 µm
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
F. Grímsson et al.
Acta Palaeobot. 56(2)
Plate 8 287
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
288 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
Plate 9
Fagaceae pollen grains from the Paleocene Agatdal Formation, Turritellakløft (Big section) locality,
Agatdalen valley, western Greenland
1. Castaneoideae PT 2, LM equatorial view (upper) and polar view (lower). IPUW 7513/182. Scale bar: 10 µm
2. Castaneoideae PT 2, SEM equatorial view, same grain as in 1. IPUW 7513/182. Scale bar: 1 µm
3. Castaneoideae PT 2, SEM, close-up of 2 showing rugulate, fossulate, perforate sculpture. IPUW 7513/182.
Scale bar: 1 µm
4. Castaneoideae PT 2, LM equatorial view (upper) and polar view (lower). IPUW 7513/183. Scale bar: 10 µm
5. Castaneoideae PT 2, SEM equatorial view, same grain as in 4. IPUW 7513/183. Scale bar: 1 µm
6. Castaneoideae PT 2, SEM, close-up of 5 showing rugulate, fossulate, perforate sculpture. IPUW 7513/183.
Scale bar: 1 µm
7. Castaneoideae PT 3, LM equatorial view (upper) and polar view (lower). IPUW 7513/184. Scale bar: 10 µm
8. Castaneoideae PT 3, SEM equatorial view, same grain as in 7. IPUW 7513/184. Scale bar: 1 µm
9. Castaneoideae PT 3, SEM, close-up of 8 showing rugulate, fossulate, perforate sculpture. IPUW 7513/184.
Scale bar: 1 µm
10. Castaneoideae PT 3, LM equatorial view (upper) and polar view (lower). IPUW 7513/185. Scale bar: 10 µm
11. Castaneoideae PT 3, SEM equatorial view, same grain as in 10. IPUW 7513/185. Scale bar: 1 µm
12. Castaneoideae PT 3, SEM, close-up of 11 showing rugulate, fossulate, perforate sculpture. IPUW 7513/185.
Scale bar: 1 µm
13. Castaneoideae PT 3, LM equatorial view (upper) and polar view (lower). IPUW 7513/186. Scale bar: 10 µm
14. Castaneoideae PT 3, SEM equatorial view, same grain as in 13. IPUW 7513/186. Scale bar: 1 µm
15. Castaneoideae PT 3, SEM, close-up of 14 showing rugulate, fossulate, perforate sculpture. IPUW 7513/186.
Scale bar: 1 µm
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
F. Grímsson et al.
Acta Palaeobot. 56(2)
Plate 9 289
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
290 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
Plate 10
Fagaceae pollen grains from the Paleocene Agatdal Formation, Turritellakløft (Big section) locality,
Agatdalen valley, western Greenland
1. Castaneoideae PT 4 (aff. Lithocarpus), LM equatorial view (upper) and polar view (lower). IPUW 7513/187.
Scale bar: 10 µm
2. Castaneoideae PT 4 (aff. Lithocarpus), SEM equatorial view, same grain as in 1. IPUW 7513/187. Scale bar: 1 µm
3. Castaneoideae PT 4 (aff. Lithocarpus), SEM, close-up of 2 showing rugulate, fossulate, perforate sculpture.
IPUW 7513/187. Scale bar: 1 µm
4. Castaneoideae PT 4 (aff. Lithocarpus), LM equatorial view. IPUW 7513/188. Scale bar: 10 µm
5. Castaneoideae PT 4 (aff. Lithocarpus), SEM equatorial view, same grain as in 4. IPUW 7513/188. Scale bar: 1 µm
6. Castaneoideae PT 4 (aff. Lithocarpus), SEM, close-up of 5 showing rugulate, fossulate, perforate sculpture.
IPUW 7513/188. Scale bar: 1 µm
7. Castaneoideae PT 4 (aff. Lithocarpus), LM equatorial view (upper) and polar view (lower). IPUW 7513/189.
Scale bar: 10 µm
8. Castaneoideae PT 4 (aff. Lithocarpus), SEM equatorial view, same grain as in 7. IPUW 7513/189. Scale bar: 1 µm
9. Castaneoideae PT 4 (aff. Lithocarpus), SEM, close-up of 8 showing rugulate, fossulate, perforate sculpture.
IPUW 7513/189. Scale bar: 1 µm
10. Castaneoideae PT 4 (aff. Lithocarpus), LM equatorial view. IPUW 7513/190. Scale bar: 10 µm
11. Castaneoideae PT 4 (aff. Lithocarpus), SEM equatorial view, same grain as in 10. IPUW 7513/190.
Scale bar: 1 µm
12. Castaneoideae PT 4 (aff. Lithocarpus), SEM close-up of 11 showing rugulate, fossulate, perforate sculpture.
IPUW 7513/190. Scale bar: 1 µm
13. Castaneoideae PT 4 (aff. Lithocarpus), LM equatorial view (upper) and polar view (lower). IPUW 7513/191.
Scale bar: 10 µm
14. Castaneoideae PT 4 (aff. Lithocarpus), SEM equatorial view, same grain as in 13. IPUW 7513/191. Scale bar: 1 µm
15. Castaneoideae PT 4 (aff. Lithocarpus), SEM, close-up of 14 showing rugulate, fossulate, perforate sculpture.
IPUW 7513/191. Scale bar: 1 µm
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
F. Grímsson et al.
Acta Palaeobot. 56(2)
Plate 10 291
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
292 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
Plate 11
Fagaceae pollen grains from the Paleocene Agatdal Formation, Turritellakløft (Big section) locality,
Agatdalen valley, western Greenland
1. Castaneoideae PT 5, LM equatorial view (upper) and polar view (lower). IPUW 7513/192. Scale bar: 10 µm
2. Castaneoideae PT 5, SEM equatorial view, same grain as in 1. IPUW 7513/192. Scale bar: 10 µm
3. Castaneoideae PT 5, SEM, close-up of 2 showing rugulate, fossulate, perforate sculpture. IPUW 7513/192.
Scale bar: 1 µm
4. Castaneoideae PT 6, LM equatorial view (upper) and polar view (lower). IPUW 7513/193. Scale bar: 10 µm
5. Castaneoideae PT 6, SEM equatorial view, same grain as in 4. IPUW 7513/193. Scale bar: 1 µm
6. Castaneoideae PT 6, SEM, close-up of 5 showing rugulate, fossulate, perforate sculpture. IPUW 7513/193.
Scale bar: 1 µm
7. Castaneoideae PT 7, LM equatorial view (upper) and polar view (lower). IPUW 7513/194. Scale bar: 10 µm
8. Castaneoideae PT 7, SEM equatorial view, same grain as in 7. IPUW 7513/194. Scale bar: 1 µm
9. Castaneoideae PT 7, SEM, close-up of 8 showing rugulate, fossulate, perforate sculpture. IPUW 7513/194.
Scale bar: 1 µm
10. Castaneoideae PT 8, LM equatorial view (upper) and polar view (lower). IPUW 7513/195. Scale bar: 10 µm
11. Castaneoideae PT 8, SEM equatorial view, same grain as in 10. IPUW 7513/195. Scale bar: 1 µm
12. Castaneoideae PT 8, SEM, close-up of 11 showing rugulate, fossulate, perforate sculpture. IPUW 7513/195.
Scale bar: 1 µm
13. Castaneoideae PT 9, LM equatorial view. IPUW 7513/196. Scale bar: 10 µm
14. Castaneoideae PT 9, SEM equatorial view, same grain as in 13. IPUW 7513/196. Scale bar: 1 µm
15. Castaneoideae PT 9, SEM, close-up of 14 showing (micro)striato-reticulate sculpture. IPUW 7513/196.
Scale bar: 1 µm
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
F. Grímsson et al.
Acta Palaeobot. 56(2)
Plate 11 293
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
294 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
Plate 12
Fagaceae pollen grains from the Eocene Princeton Chert beds, Allenby Formation,
British Columbia, Canada
1. Paraquercus eocaena, LM equatorial view. Holotype, IPUW 7513/197. Scale bar: 10 µm
2. Paraquercus eocaena, SEM equatorial view, same grain as in 1. Holotype, IPUW 7513/197. Scale bar: 10 µm
3. Paraquercus eocaena, SEM, close-up of 2, showing parallel to radially arranged (micro)rugulae in groups.
Holotype, IPUW 7513/197. Scale bar: 1 µm
4. Eotrigonobalanus PT, LM equatorial view. IPUW 7513/198. Scale bar: 10 µm
5. Eotrigonobalanus PT, SEM equatorial view, same grain as in 4. IPUW 7513/198. Scale bar: 1 µm
6. Eotrigonobalanus PT, SEM, close-up of 5, showing twisted and interwoven microrugulae. IPUW 7513/198.
Scale bar: 1 µm
7. Trigonobalanopsis PT, LM equatorial view. IPUW 7513/199. Scale bar: 10 µm
8. Trigonobalanopsis PT, SEM equatorial view, same grain as in 7. IPUW 7513/199. Scale bar: 10 µm
9. Trigonobalanopsis PT, SEM, close-up of 8, showing rugulate sculpture, rugulae conspicuously segmented.
IPUW 7513/199. Scale bar: 1 µm
10. Trigonobalanopsis PT, SEM equatorial view. IPUW 7513/200. Scale bar: 10 µm
11. Trigonobalanopsis PT, SEM, close-up of 10, showing rugulae irregularly arranged or parallel in small
groups, rugulae conspicuously segmented. IPUW 7513/200. Scale bar: 1 µm
12. Trigonobalanopsis PT, SEM equatorial view. IPUW 7513/201. Scale bar: 10 µm
13. Trigonobalanopsis PT, SEM, close-up of 12, showing rugulae and perforate sculpture. IPUW 7513/201.
Scale bar: 1 µm
14. Castaneoideae PT 2, LM equatorial view. IPUW 7513/202. Scale bar: 10 µm
15. Castaneoideae PT 2, SEM equatorial view, same grain as in 14. IPUW 7513/202. Scale bar: 10 µm
16. Castaneoideae PT 2, SEM, close-up of 15, showing rugulate sculpture around colpi. IPUW 7513/202.
Scale bar: 1 µm
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
F. Grímsson et al.
Acta Palaeobot. 56(2)
Plate 12 295
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
296 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
Plate 13
Fagaceae pollen grains from the Eocene Princeton Chert beds, Allenby Formation,
British Columbia, Canada
1. Fagoideae PT 2, LM equatorial view, pori elliptic (lolongate). IPUW 7513/203. Scale bar: 10 µm
2. Fagoideae PT 2, SEM equatorial view, same grain as in 1. IPUW 7513/203. Scale bar: 10 µm
3. Fagoideae PT 2, SEM, close-up of 2, showing rugulate and minutely fossulate sculpture, rugulae not pro-
truding. IPUW 7513/203. Scale bar: 1 µm
4. Fagus PT 2, LM equatorial view, pori small circular. IPUW 7513/204. Scale bar: 10 µm
5. Fagus PT 2, SEM equatorial view, same grain as in 4. IPUW 7513/204. Scale bar: 1 µm
6. Fagus PT 2, SEM, close-up of 5, showing microrugulate to rugulate and minutely fossulate sculpture, tips
of rugulae sometimes protruding. IPUW 7513/204. Scale bar: 1 µm
7. Fagus PT 3, LM equatorial view (upper), polar view (lower), pori elliptic (lolongate). IPUW 7513/205.
Scale bar: 10 µm
8. Fagus PT 3, SEM polar view, same grain as in 7, colpi extending from pole to pole. IPUW 7513/205.
Scale bar: 10 µm
9. Fagus PT 3, SEM, close-up of 8, showing microrugulate sculpture. IPUW 7513/205. Scale bar: 1 µm
10. Fagus PT 3, SEM, close-up of 8, showing microrugulate sculpture, tips of rugulae often protruding. IPUW
7513/205. Scale bar: 1 µm
11. Quercus PT 1 (aff. Group Lobatae), LM equatorial view. IPUW 7513/206. Scale bar: 10 µm
12. Quercus PT 1 (aff. Group Lobatae), SEM equatorial view, same grain as in 11. IPUW 7513/206. Scale bar: 1 µm
13. Quercus PT 1 (aff. Group Lobatae), SEM, close-up of 12, showing (micro)verrucate, fossulate and perforate
sculpture. IPUW 7513/206. Scale bar: 1 µm
14. Quercus PT 2 (ancestral type with Group Ilex morphology), LM equatorial view. IPUW 7513/207.
Scale bar: 10 µm
15. Quercus PT 2 (ancestral type with Group Ilex morphology), SEM equatorial view, same grain as in 14.
IPUW 7513/207. Scale bar: 10 µm
16. Quercus PT 2 (ancestral type with Group Ilex morphology), SEM, close-up of 15, showing microrugulate and
perforate sculpture. IPUW 7513/207. Scale bar: 1 µm
17. Quercus PT 2 (ancestral type with Group Ilex morphology), LM equatorial view. IPUW 7513/208. Scale bar: 10 µm
18. Quercus PT 2 (ancestral type with Group Ilex morphology), SEM equatorial view, same grain as in 17.
IPUW 7513/208. Scale bar: 10 µm
19. Quercus PT 2 (ancestral type with Group Ilex morphology), SEM, close-up of 18, showing microrugulate and
perforate sculpture. IPUW 7513/208. Scale bar: 1 µm
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
F. Grímsson et al.
Acta Palaeobot. 56(2)
Plate 13 297
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
298 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
Plate 14
Fagaceae and Fagales leaves from the Paleogene of western Greenland
1. Fagaceae indet., large lamina, MGUH 6526. Qeqertarsuatsiaq, Hareøen Fm. Scale bar: 1 cm
2. Fagaceae indet., close-up of 1, showing teeth and venation in lower half of lamina, wide rounded sinuses
between teeth, MGUH 6526. Qeqertarsuatsiaq, Hareøen Fm. Scale bar: 1 cm
3. Fagopsiphyllum groenlandicum, part of large lamina, MGUH 6550. Qeqertarsuatsiaq, Hareøen Fm.
Scale bar: 1 cm
4. Fagales indet., part of large lamina, MGUH 6552. Referred to Qeqertarsuatsiaq (Hareøen) by Heer (1883).
Most likely from Upper Atanikerluk A, Quikavsak Fm. Scale bar: 1 cm
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
F. Grímsson et al.
Acta Palaeobot. 56(2)
Plate 14 299
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
300 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
Plate 15
Fagaceae and Fagales leaves from the Paleogene of western Greenland
1. Fagopsiphyllum groenlandicum, part of lamina, MGUH 6538. Referred to Qeqertarsuatsiaq (Hareøen) by
Heer (1883). Most likely from Upper Atanikerluk A, Quikavsak Fm (see Note under species description).
Scale bar: 1 cm
2. Fagopsiphyllum groenlandicum, part of lamina, counterpart to 1, MGUH 6538. Referred to Qeqertarsuatsiaq
(Hareøen) by Heer (1883). Most likely from Upper Atanikerluk A, Quikavsak Fm (see Note under species
description). Scale bar: 1 cm
3. Fagopsiphyllum groenlandicum, close-up of 1, showing teeth, MGUH 6538. Referred to Qeqertarsuatsiaq
(Hareøen) by Heer (1883). Most likely from Upper Atanikerluk A, Quikavsak Fm (see Note under species
description). Scale bar: 1 cm
4. Fagopsiphyllum groenlandicum, narrow elliptic lamina, MGUH 6542. Referred to Qeqertarsuatsiaq (Hareøen)
by Heer (1883). Most likely from Upper Atanikerluk A, Quikavsak Fm (see Note under species description).
Scale bar: 1 cm
5. Fagopsiphyllum groenlandicum, close-up of 4, showing secondary and tertiary venation and teeth along
margin, MGUH 6542. Referred to Qeqertarsuatsiaq (Hareøen) by Heer (1883). Most likely from Upper Atani-
kerluk A, Quikavsak Fm (see Note under species description). Scale bar: 1 cm
6. Fagopsiphyllum groenlandicum, close-up of Pl. 14, g. 3, showing secondary venation and teeth along mar-
gin, wide angular sinuses between teeth, MGUH 6550. Qeqertarsuatsiaq, Hareøen Fm. Scale bar: 1 cm
7. Fagales indet., close-up of Pl. 14, g. 4, showing secondary and tertiary venation and teeth along margin,
subsidiary teeth present, MGUH 6552. Referred to Qeqertarsuatsiaq (Hareøen) by Heer (1883). Most likely
from Upper Atanikerluk A, Quikavsak Fm Scale bar: 1 cm
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
F. Grímsson et al.
Acta Palaeobot. 56(2)
Plate 15 301
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
302 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
Plate 16
Fagus leaves from the Eocene of Qeqertarsuatsiaq, Hareøen Formation, western Greenland
1. Fagus cordifolia, leaf, broadly based lamina, almost complete, MGUH 6558. Scale bar: 1 cm
2. Fagus cordifolia, leaf, close-up of 1, showing venation along margin, MGUH 6558. Scale bar: 1 cm
3. Fagus leaf morphotype 2, leaf, part of large lamina, S 110240. Scale bar: 1 cm
4. Fagus leaf morphotype 2, leaf, close-up of 3, showing base, S 110240. Scale bar: 1 cm
5. Fagus leaf morphotype 2, leaf, close-up of 3, showing tertiary venation and basal-most tooth above base,
S 110240. Scale bar: 1 cm
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
F. Grímsson et al.
Acta Palaeobot. 56(2)
Plate 16 303
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
304 F. Grímsson et al. / Acta Palaeobotanica 56(2): 247–305, 2016
Plate 17
Fagus leaves from the Eocene of Qeqertarsuatsiaq, Hareøen Formation, western Greenland
1. Fagus leaf morphotype 2, leaf, part of lamina, S 109724. Scale bar: 1 cm
2. Fagus leaf morphotype 2, leaf, close-up of 1, showing secondary and higher-order venation and teeth in cen-
tral part of lamina, S 109724. Scale bar: 1 cm
3. Fagus leaf morphotype 2, leaf, close-up of 1, showing secondary and higher-order venation and teeth in lower
part of lamina, S 109724. Scale bar: 1 cm
4. Fagus leaf morphotype 2, leaf, part of large lamina, S 110238. Scale bar: 1 cm
5. Fagus leaf morphotype 2, leaf, close-up of 4, showing secondary and higher-order venation and teeth in cen-
tral part of lamina, S 110238. Scale bar: 1 cm
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
F. Grímsson et al.
Acta Palaeobot. 56(2)
Plate 17 305
Bereitgestellt von | Vienna University Library
Angemeldet
Heruntergeladen am | 21.12.16 11:27
... It is a small but ecologically and economically important genus of about ten monoecious tree species occurring in three isolated regions of the Northern Hemisphere: East Asia, western Eurasia, and eastern North America (Denk, 2003;Fang and Lechowicz, 2006;Peters, 1997;Shen, 1992). The genus probably originated at high latitudes during the Paleocene (western Greenland, northeast Asia; Denk and Grimm, 2009;Fradkina et al., 2005;Gr ımsson et al., 2016). It is subdivided into two informal subgenera (Denk et al., 2005;Shen, 1992 Renner et al., 2016). ...
... It is subdivided into two informal subgenera (Denk et al., 2005;Shen, 1992 Renner et al., 2016). While the lineage leading to the modern genus is at least 82-81 myrs old (Gr ımsson et al., 2016), extant species are the product of approximately 50 myrs of trans-continental range expansion and phases of fragmentation leading to diversification (Denk, 2004;Denk and Grimm, 2009;Renner et al., 2016). These dynamic migration and speciation histories left multifarious morphological and molecular imprints on modern members of the genus (Figure 1). ...
... The pronounced ancient nuclear polymorphism, also a predominant feature in Jiang et al. (2021) data, implies that modern beeches are of hybrid or allopolyploid origin. Our 5S-IGS data clearly indicate a hybrid origin for the species of Subgenus Engleriana, with the F. japonica I-Lineage variants representing common ancestry with Subgenus Fagus (Eurasian clade), while the outgroup variant (O-Lineage) represents another, potentially extinct, lineage of high-latitude beeches (Denk and Grimm, 2009; see also Fradkina et al., 2005;Gr ımsson et al., 2016). Hybrid/ allopolyploid origins would also explain the great divergence observed in the ITS region of Fagus, especially Subgenus Engleriana (Denk et al., 2005), a lineage with a poorly sorted nucleome and still sharing AE primitive genotypes with North American and East Asian members of Subgenus Fagus (Data S5). ...
Article
Full-text available
Standard models of plant speciation assume strictly dichotomous genealogies in which a species, the ancestor, is replaced by two offspring species. The reality in wind‐pollinated trees with long evolutionary histories is more complex: species evolve from other species through isolation when genetic drift exceeds gene flow; lineage mixing can give rise to new species (hybrid taxa such as nothospecies and allopolyploids). The multi‐copy, potentially multi‐locus 5S rDNA is one of few gene regions conserving signal from dichotomous and reticulate evolutionary processes down to the level of intra‐genomic recombination. Therefore, it can provide unique insights into the dynamic speciation processes of lineages that diversified tens of millions of years ago. Here, we provide the first high‐throughput sequencing (HTS) of the 5S intergenic spacers (5S‐IGS) for a lineage of wind‐pollinated subtropical to temperate trees, the Fagus crenata – F. sylvatica s.l. lineage, and its distant relative F. japonica. The observed 4,963 unique 5S‐IGS variants reflect a complex history of hybrid origins, lineage sorting, mixing via secondary gene flow, and intra‐genomic competition between two or more paralogous‐homoeologous 5S rDNA lineages. We show that modern species are genetic mosaics and represent a striking case of ongoing reticulate evolution during the past 55 million years.
... Ilex) and include evergreen groups (many Castaneoideae), mixed evergreen/ deciduous groups (Quercus), and purely deciduous groups (Fagus, Castanea). This vast ecological diversity evolved since the Late Cretaceous (Herendeen et al., 1995;Takahashi et al., 2008;Friis et al., 2011;Grímsson et al., 2016b;Sadowski et al., 2018). In addition to their modern diversity, the Fagaceae have a remarkably rich and well-preserved fossil record throughout the Cenozoic (e.g., Mai, 1970Mai, , 1989Crepet and Daghlian, 1980;Manchester and Crane, 1983;Kvaček and Walther, 1988,b, 1991, 2010Crepet, 1989;Crepet and Nixon, 1989a,b;Walther and Zetter, 1993;Mindell et al., 2007Mindell et al., , 2009Denk et al., 2010Denk et al., , 2012Denk et al., , 2017aDenk et al., , 2017bDenk et al., , 2017cDenk et al., , 2019aGrímsson et al., 2015;Pavlyutkin, 2015;Grímsson, et al., 2016aGrímsson, et al., , 2016bWilf et al., 2019) making them a key group for investigating the development of northern hemispheric forest ecosystems through time and to test responses of woody plants to major climatic changes during the past 60 million years. ...
... This vast ecological diversity evolved since the Late Cretaceous (Herendeen et al., 1995;Takahashi et al., 2008;Friis et al., 2011;Grímsson et al., 2016b;Sadowski et al., 2018). In addition to their modern diversity, the Fagaceae have a remarkably rich and well-preserved fossil record throughout the Cenozoic (e.g., Mai, 1970Mai, , 1989Crepet and Daghlian, 1980;Manchester and Crane, 1983;Kvaček and Walther, 1988,b, 1991, 2010Crepet, 1989;Crepet and Nixon, 1989a,b;Walther and Zetter, 1993;Mindell et al., 2007Mindell et al., , 2009Denk et al., 2010Denk et al., , 2012Denk et al., , 2017aDenk et al., , 2017bDenk et al., , 2017cDenk et al., , 2019aGrímsson et al., 2015;Pavlyutkin, 2015;Grímsson, et al., 2016aGrímsson, et al., , 2016bWilf et al., 2019) making them a key group for investigating the development of northern hemispheric forest ecosystems through time and to test responses of woody plants to major climatic changes during the past 60 million years. ...
... Specifically, the tectum is made up of the same basic elements, called rodlets or tufts, which form different sculpturing (Kohlmann-Adamska and Ziembińska-Tworzydło, 2000; Denk and Grimm, 2009a). Similar structures as encountered in Tricolporopollenites pseudocingulum are present in Quercus and in extinct fagaceous genera of Eurasia and North America (Crepet and Nixon, 1989;Denk et al., 2012;Grímsson et al., 2015Grímsson et al., , 2016bPrader et al., 2020). This pollen type has previously been reported from middle Miocene strata of Poland (Stuchlik et al., 2014) but has not been reported from coeval or slightly younger strata in Central Europe and Asia Minor, nor from Iceland (Denk et al., 2011;Grímsson et al., 2016a;Bouchal et al., 2017). ...
Article
Full-text available
Premise: The Fagaceae comprise around 1000 tree species in the Northern Hemisphere. Despite an extensive fossil pollen record, reconstructing biogeographic patterns is hampered because it is difficult to achieve good taxonomic resolution with light microscopy alone. We investigate dispersed pollen of Fagaceae from the Miocene Søby flora, Denmark. We explore the latitudinal gradient in Fagaceae distribution during the Miocene Climatic Optimum (MCO) in Europe and the Northern Hemisphere to compare it with the Eocene Warmhouse and the present. Methods: We investigated dispersed pollen using light and scanning electron microscopy. We assessed biogeographic patterns in Fagaceae during two warm periods in Earth history (MCO, Eocene) and the present. Results: Eight species of Fagaceae were recognized in the Søby flora. Of these, Fagus had a continuous Mediterranean to subarctic distribution during MCO; Quercus sect. Cerris and castaneoids had northern limits in Denmark, and evergreen Quercus sect. Ilex in Central Europe. In a northern hemispheric context, Fagus and sections of Quercus had more northerly distribution limits during Eocene and MCO with maximum northward extensions during Eocene (Fagus, castaneoids) or Oligo-Miocene (Quercus sects. Cerris and Ilex). The known distribution of the extinct Tricolporopollenites theacoides during MCO included Central Europe and East China, while this taxon thrived in South China during Eocene. Conclusions: More northerly distributions during MCO and Eocene probably were determined by temperature. In contrast, fossil occurrences in areas that are arid or semi-humid today were determined by maritime conditions in these areas (western North America, Central Asia) during the Cenozoic.
... Palaeocarpological fossils of Fagus from the Chattian and Aquitanian localities Dunayevski Yar and Belyi Yar were identified (Dorofeev 1960;Dorofeev 1963) (Table 6 (Pigg & Wehr 2002;Manchester & Dillhoff 2004;Grímsson et al. 2016). Floras of middle to late Eocene ages from Alaska, Greenland, China, Kamchatka Peninsula, and Japan indicate that the genus was widely distributed across the Northern Hemisphere (Tanai 1955;Spicer et al. 1987;Budantsev 1997;Wang et al. 2010;Clifton 2012;Grímsson et al. 2016). ...
... Palaeocarpological fossils of Fagus from the Chattian and Aquitanian localities Dunayevski Yar and Belyi Yar were identified (Dorofeev 1960;Dorofeev 1963) (Table 6 (Pigg & Wehr 2002;Manchester & Dillhoff 2004;Grímsson et al. 2016). Floras of middle to late Eocene ages from Alaska, Greenland, China, Kamchatka Peninsula, and Japan indicate that the genus was widely distributed across the Northern Hemisphere (Tanai 1955;Spicer et al. 1987;Budantsev 1997;Wang et al. 2010;Clifton 2012;Grímsson et al. 2016). In addition, Fagus pollen has been reported from the middle Eocene sediments of Axel Heiberg Island, Canada (McIntyre 1991) and Kamchatka (Budantsev 1997;Grímsson et al. 2015). ...
... But, pollen of Fagus has been identified from an early Oligocene (Rupelian) assemblage at Cospuden in central Germany and they are currently the oldest record of the genus in Europe (Denk et al. 2012). Although the North Atlantic land bridges were available, the plant fossil record supports the current hypothesis that Fagus migrated from Asia into Europe once the West Siberian Sea regressed (Grímsson et al. 2015;Grímsson et al. 2016). Today, Fagus consists of 10 species and it is a common element of the temperate broad-leaved deciduous forests in eastern North America, eastern Asia, and Europe/west Asia (Wang 1961;Willis 1966;Denk 2003;Fang & Lechowicz 2006). ...
Article
Full-text available
In this study, we describe the fossil wood flora from the Chattian (late Oligocene) and Aquitanian (early Miocene) deposits that crop out on the Tym River at Kompasky Bor, Russia. Twenty conifer and angiosperm wood taxa are described and a new fossil wood genus Thujopsoxylon gen. nov. and three new species are established: Thujopsoxylon schneiderianum sp. nov.; Piceoxylon nikitinii sp. nov.; and Crataegoxylon sibiricum sp. nov. The Kompasky Bor flora is important because it is the northernmost Chattian macroflora in the West Siberian Plain so far known and provides constraints on the timing and record of plant taxa migrations between Europe and the West Siberian Plain during the late Paleogene and the early Neogene. The fossil wood and macrofossil taxa are compared to European and other West Siberian Plain floras of similar age to understand the spatial and temporal relationships between these floras. The results of this multivariate analysis indicate floristic exchange between Europe and the West Siberian Plain was not prevalent, but much more pronounced between the West Siberian Plain and the Ural Mountains during the Rupelian and Chattian. Furthermore, elements of the polar broad-leaved deciduous forests appear to have occupied northern Europe and extended into the Ural Mountains and, despite the functionality of the lowland corridors between Europe and the West Siberian Plain, floristic exchange was not pronounced until Miocene time when climate became cooler and drier, signaling the onset of the evolution and development of boreal ecosystems in Europe and the West Siberian Plain.
... This assessment of high-latitude fossil plants, and their alleged close relationship to the modern northern temperate woody flora, brought Engler (1879) to establish the term 'Arcto-Tertiary element', used for plant groups that today dominate temperate forest regions and have prominent fossil representatives in Paleogene floras at high latitudes. Later authors considered many of the fossils to represent extinct taxa, commonly with unknown botanical affinities (Koch 1963;Boulter and Kvaček 1989;Kvaček et al. 1994;Mai 1995;Manchester 1999 r e e n l a n d I c e l a n d F a r o e I s l a n d s B r i t i s h I s l e s and Golovneva (2009) and Grímsson et al. (2015Grímsson et al. ( , 2016a suggested that a substantial number of alleged extinct taxa actually belong to modern genera (Aesculus, Alnus, Betula, Carpinus, Fagus, Quercus and Ulmus), thus supporting Engler's hypothesis about the 'Arcto-Tertiary element'. Neogene plant fossils from the sub-arctic North Atlantic have recently been shown to be important for understanding modern biogeographic patterns in northern temperate plant groups and assessing the subsidence history of the Greenland-Scotland Transverse Ridge (Tiffney and Manchester 2001;Grímsson and Denk 2007;Tiffney 2008;Denk et al. 2010aDenk et al. , 2011. ...
... However, Mai (1995) pointed to the presence of the extinct Fagaceae Eotrigonobalanus in the early Palaeocene flora of Atanikerluk, along with several other extinct types of Fagaceae. This observation has recently been confirmed by both pollen and leaf fossils from Agatdalen (Grímsson et al. 2016a(Grímsson et al. , 2016b. Koch (1963) Koch (1963) recognized the extant genus Liriodendron ( Figure 3B) but placed leaf imprints similar to modern Sassafras ( Figure 3C) within the extinct genus Lauraceaephyllum based on subtle differences in venation between the fossil and the modern genus. ...
... Koch (1963) Koch (1963) recognized the extant genus Liriodendron ( Figure 3B) but placed leaf imprints similar to modern Sassafras ( Figure 3C) within the extinct genus Lauraceaephyllum based on subtle differences in venation between the fossil and the modern genus. Revision of the Agatdalen macroflora by Grímsson et al. (2016a) reduces the ca. 38 taxa by Koch (1963) down to ca. 32. ...
Chapter
This chapter reviews Cenozoic plant assemblages from the sub-arctic North Atlantic region and their biogeographic implications. Engler's hypothesis about the ‘Arcto-Tertiary element’ remains a fundamental hypothesis about the origin of northern temperate tree genera. The book reviews previous work on the plant fossil record from Paleocene to Pleistocene sedimentary formations of the sub-arctic North Atlantic region. This includes Paleogene plant assemblages from Greenland, the Faroe Islands and Scotland, as well as Neogene floras from Iceland. The Faroe Islands are patchy sub-aerial remnants of a extensive Paleogene lava sequence that is considered part of the Brito-Arctic Igneous Province. In his classic paper from 1985, Tiffney mentions plant genera that are shared between the early Miocene Brandon Lignite Flora of eastern North America and Paleogene and Neogene floras of western Eurasia to illustrate the importance of the North Atlantic Land Bridge. The improved understanding of the history of the NALB is crucial for basic biogeographic assumptions.
... Fagus L. (Fagaceae) is a small but ecologically and economically important genus of about ten monoecious tree species occurring in three isolated regions of the Northern Hemisphere: East Asia, western Eurasia, and (eastern) North America (Shen, 1992;Peters, 1997;Denk, 2003;Fang & Lechowicz, 2006). The genus is monophyletic and might have originated at high latitudes during the Paleocene (western Greenland, northeast Asia; Fradkina et al., 2005;Denk & Grimm, 2009;Grímsson et al., 2016). It is currently subdivided into two informal subgenera corresponding to reciprocally monophyletic lineages (Shen, 1992;Denk et al., 2005). ...
... (Renner et al., 2016), including the oldest unambiguous macrofossil record of the genus (Manchester & Dillhoff, 2004). While the lineage leading to the modern genus is at least 82-81 myrs old (Grímsson et al., 2016), the extant species are the product of ~50 myrs of trans-continental range expansion and phases of fragmentation leading to diversification (Denk, 2004;Denk & Grimm, 2009). These dynamic migration and speciation histories left multifarious morphological and molecular imprints on modern members of the genus. ...
... Pronounced ancient nuclear polymorphism implies that at least some modern beeches are of hybrid or allopolyploid origin. For the species of 'subgenus Engleriana' a hybrid origin would make sense, with the F. japonica ingroup variants representing the common ancestry with the Eurasian clade of 'subgenus Fagus', while the outgroup variant represents another, potentially extinct, lineage of high-latitude beeches (Denk & Grimm, 2009; see also Fradkina et al., 2005;Grímsson et al., 2016). A hybrid/allopolyploid origin would also explain the extreme divergence observed in the ITS region of Fagus (Denk et al., 2005) and appears to be supported . ...
Preprint
Full-text available
Standard models of speciation assume strictly dichotomous genealogies in which a species, the ancestor, is replaced by two offspring species. The reality is more complex: plant species can evolve from other species via isolation when genetic drift exceeds gene flow; lineage mixing can give rise to new species (hybrid taxa such as nothospecies and allopolyploids). The multi-copy, potentially multi-locus 5S rDNA is one of few gene regions conserving signal from dichotomous and reticulate evolutionary processes down to the level of intra-genomic recombination. Here, we provide the first high-throughput sequencing (HTS) 5S intergenic spacer (5S-IGS) data for a lineage of wind-pollinated subtropical to temperate trees, the Fagus crenata – F. sylvatica s.l. lineage, and its distant relative F. japonica . The observed 4,963 unique 5S-IGS variants reflect a long history of repeated incomplete lineage sorting and lineage mixing since the early Cenozoic of two or more paralogous-homoeologous 5S rDNA lineages. Extant species of Fagus are genetic mosaics and, at least to some part, of hybrid origin. Significance statement The evolution of extra-tropical tree genera involves dynamic speciation processes. High-throughput sequencing data of the multi-copy, potentially multi-locus 5S rDNA reveal a complex history of hybrid origins, lineage sorting and mixing, and intra-genomic competition between paralogous-homeologous loci in the core group of Eurasian beech trees (genus Fagus ) and their distant relative, F. japonica . The modern species are genetic mosaics and represent a striking case of at least 35 million years of ongoing reticulate evolution.
... Fossils of modern Fagaceae are well represented in the Northern Hemisphere, indicating long-term presence and differential patterns of diversification [30][31][32][33][34][35][36][37][38][39][40] . Recent studies integrating these fossils within phylogenies of modern taxa have provided essential context to estimate divergence times [41][42][43] . ...
Article
Full-text available
Northern Hemisphere forests changed drastically in the early Eocene with the diversification of the oak family (Fagaceae). Cooling climates over the next 20 million years fostered the spread of temperate biomes that became increasingly dominated by oaks and their chestnut relatives. Here we use phylogenomic analyses of nuclear and plastid genomes to investigate the timing and pattern of major macroevolutionary events and ancient genome-wide signatures of hybridization across Fagaceae. Innovation related to seed dispersal is implicated in triggering waves of continental radiations beginning with the rapid diversification of major lineages and resulting in unparalleled transformation of forest dynamics within 15 million years following the K-Pg extinction. We detect introgression at multiple time scales, including ancient events predating the origination of genus-level diversity. As oak lineages moved into newly available temperate habitats in the early Miocene, secondary contact between previously isolated species occurred. This resulted in adaptive introgression, which may have further amplified the diversification of white oaks across Eurasia.
... Vasicentric tracheids, the occurrence of which is often correlated with wide and exclusively solitary vessels (Carlquist 1984(Carlquist , 2001, are common in the Castaneoideae and rare in the Fagoideae. Grimmson et al. (2016) suggested that Fagus L. split from other Fagaceae by the Late Cretaceous. ...
... The observed difference is essential for the identification of dispersed fossil fagaceous leaves. Often the pattern of tooth disposition, density, shape, and size are important distinctive characters used for erecting new species (e.g., Chelebaeva, 1980;Iljinskaya, 1982;Leng, 1999;Kvaček et al., 2011;Grímsson et al., 2016;Barrón et al., 2017). ...
Article
Premise: Microclimatic differences between the periphery and the interior of tree crowns result in a variety of adaptive leaf macromorphological and anatomical features. Our research was designed to reveal criteria for sun/shade leaf identification in two species of evergreen oaks, applicable to both modern and fossil leaves. We compared our results with those in other species similarly studied. Methods: For both Quercus bambusifolia and Q. myrsinifolia (section Cyclobalanopsis), leaves from single mature trees with well-developed crowns were collected in the South China Botanical Garden, Guangzhou, China. We focus on leaf characters often preserved in fossil material. SVGm software was used for macromorphological measurement. Quantitative analyses were performed and box plots generated using R software with IDE Rstudio. Leaf cuticles were prepared using traditional botanical techniques. Results: Principal characters for distinguishing shade and sun leaves in the studied oaks were identified as leaf lamina length to width ratio (L/W), and the degree of development of venation networks. For Q. myrsinifolia, shade and sun leaves differ in tooth morphology and the ratio of toothed lamina length to overall lamina length. The main epidermal characters are ordinary cell size and anticlinal wall outlines. For both species, plasticity within shade leaves exceeds that of sun leaves. Conclusions: Morphological responses to sun and shade in the examined oaks are similar to those in other plant genera, pointing to useful generalizations for recognizing common foliar polymorphisms that must be taken into account when determining the taxonomic position of both modern and fossil plants.
... Sampson 2000). The same is true within the Fagales for Fagaceae with their exclusively tricol(por)ate pollen (Grímsson et al. 2016) and the monotypic Nothofagaceae which are polycolporate (Fernández et al. 2016). Triporate pollen superficially similar to that recovered from our fossils today is limited to Fagales sensu APG III (2009) and APG IV (2016), especially to a distinct clade (Li et al. 2004) comprising Betulaceae, Casuarinaceae, Juglandaceae, Myricaceae, Rhoipteleaceae (now included in Juglandaceae: APG III 2009), and Ticodendraceae. ...
Article
Full-text available
The late middle Eocene lacustrine filling of a maar lake at Eckfeld (Eifel Hills, Rhineland-Palatinate, western Germany) has provided four specimens of male inflorescences (catkins) in different stages of anthesis, each with pollen preserved in situ. The appearance of the successive stages together with triporate pollen showing an irregular surface and a myricoid micro-ornamentation clearly suggests an assignment of the fossil catkins to the Myricaceae. The material is described as a new genus and new species and represents the oldest record of male catkins for the family. The in situ preserved pollen grains are comparable to dispersed grains of Triatriopollenites excelsus.
Thesis
Full-text available
My PhD’s thesis aims to clarify the biosystematic relationships and taxonomical status among some critical taxa of European white oaks in southern Italy. This group, more commonly called pubescent oaks (sensu Di Pietro et. al., 2018) is composed of Quercus amplifolia Guss., Q. apennina Lam., Q. congesta C.Presl., Q. dalechampii Ten., Q. humilis DC, Q. ichnusae Mossa, Bacch. & Brullo, Q. leptobalana Guss.5, Q. virgiliana (Ten.) Ten. Some of these taxa are considered as ”doubtful” species since they exhibit a large overlapping of morphological and ecological characters and are oftentimes found in sympatry. For these reasons, these species are frequently attributed to the group of Q. pubescens s.l. (sensu lato).
Conference Paper
Full-text available
Microstructure of Fagaceae pollen from Austria (Palaeocene/Eocene boundary) and Hainan island (?Middle Eocene). Hofmann, Ch.-Ch. The exine microstructures of fossil fagaceous pollen have been investigated with LM and SEM to demonstrate the variety of exine patterns and probable palaeo-diversity in different Eocene localities. In the Austrian palynomorph assemblages ancient Fagaceae, such as different Eotrigonobalanopsis types occur, only accessorily. In contrast, the Chinese locality is much more diverse with different “evergreen oaks-types”, probable “deciduous oak” forms, and Lithocarpus-like taxa dominate most of the palynomorph assemblages. The “evergreen oak” types are far more common and diverse than the probable “deciduous oak” types. In comparison with exine microstructures of extant Fagaceae, such as Quercus taxa, the individual “evergreen oak” types show some similarities with the infrageneric “ilex group” (Denk & Grimm, 2009), or probable mixed types between the infrageneric “ilex group” and Cyclobalanopsis, infrageneric “lobatae group” (Denk & Grimm, 2009) and the already extinct Eotrigonobalanus types, or Eotrigonobalus. The probable “deciduous oak” types cannot be associated so far.
Article
Full-text available
Hybridization plays a major role in speciation. However, hybridization and reticulate evolution in general are poorly understood in tree species because genetic documentation is often missing. Analyses of biparentally inherited gene regions allow detection of reticulate signals. Multicopy and single‐copy nuclear markers may show significant intraindividual variability owing to reticulation processes. Naturally, such processes induce incompatible phylogenetic signal resulting in incongruent genealogies. Data from three nuclear markers, two multicopy nrDNA spacers, and the single‐copy 2nd intron of the LEAFY gene, mirror ancient and recent horizontal gene flow in plane trees (Platanus). In addition to previously assembled data from the internal transcribed spacers (ITS) of the 35S ribosomal DNA, we found atypical 5S rDNA intergenic spacer sequences (5S‐IGS) causing significant intra‐ and interindividual polymorphism, and a conspicuous LEAFY intron dimorphism. A detailed framework of reticulate molecular evolution of Platanus can be erected using splits graphs based on distances between cloned sequences or individuals, and competing topologies. Two hundred and sixty‐one 5S‐IGS sequences and LEAFY genotyping of 71 individuals via sequence analysis and PCR‐RFLP support a previous ITS study (including pseudogenous and non‐pseudogenous variants) suggesting that the modern North American taxa P. rzedowskii and P. occidentalis var. palmeri are the result of ancient hybridization. Platanus occidentalis var. palmeri requires taxonomic revision and is provisionally treated at species rank.
Book
Full-text available
This open access book offers a fully illustrated compendium of glossary terms and basic principles in the field of palynology, making it an indispensable tool for all palynologists. It is a revised and extended edition of “Pollen Terminology. An illustrated handbook,” published in 2009. This second edition, titled “Illustrated Pollen Terminology” shares additional insights into new and stunning aspects of palynology. In this context, the general chapters have been critically revised, expanded and restructured. The chapter “Misinterpretations in Palynology” has been extended with new research data and additional ambiguous terms, e.g., polyads vs. massulae; the chapter “Methods in Palynology” has been extensively enhanced with illustrated protocols showing the majority of the methods and techniques used when studying recent and fossil pollen with LM, SEM and TEM. Moreover, additional information about the description and publication of pollen data is provided in the chapter “How to Describe and Illustrate Pollen Grains.” Various other parts of the general chapters have now been updated and/or extended with more comprehensive textual passages and new illustrations. The chapter “Illustrated Pollen Terms” now features new and more appropriate examples of each term, including additional LM micrographs. Where necessary, the entries for selected pollen terms have been refined by rewording or adding definitions, illustrations, and new micrographs. Lastly, new terms are included, such as “suprasculpture” and the prefix “nano-“ for ornamentation features. The chapter “Illustrated Pollen Terms” is the main part of this book and comprises more than 300 widely used terms illustrated with over 1,000 high-quality images. It provides a detailed survey of the manifold ornamentation and structures of pollen, and offers essential insights into their stunning beauty. Springer link: http://www.springer.com/de/book/9783319713649
Article
Full-text available
The Cretaceous and Palaeogene floras of western Greenland that were initially described as part of the classical work “Flora fossilis arctica” by Oswald Heer in the 19th century are currently under revision. The Nuussuaq Basin has repeatedly been investigated by geologists and marine invertebrate palaeontologists. These studies provide a modern stratigraphic framework and a basis for revisions of various Cretaceous to Eocene floras from this region, and the correlation of fossil material to stratigraphic units and formal formations. This paper is the first in a series of papers that (i) correlate macrofossil (museum) material and fossil-rich localities with the modern lithostratigraphic framework, (ii) describe new pollen, spores, and other marine/freshwater palynomorphs, and (iii) revise the macrofossil remains from the Agatdalen area (particularly the Danian Agatdal Formation). Since the work of B. Eske Koch in the 1960s and 70s, questions emerged about the correlation of plant fossiliferous outcrops and whether the so-called Agatdalen flora, referred to the Agatdal Formation, originates from a single sedimentary unit or not. In this paper, we summarise the stratigraphy of the Agatdalen area and correlate the fossil plant-bearing outcrops described by Koch to the current lithostratigraphy. We establish which plant fossils belong to the Agatdal Formation and re-assign a great number of other plant fossils to their correct formations. New palynological material is briefly described and correlated to the macrofossil localities and the Agatdal Formation. Previous accounts on the macrofossils (leaves, fruits, seeds) are briefly discussed and directions for future revisions are outlined.
Article
Full-text available
The fossilized birth–death (FBD) model can make use of information contained in multiple fossils representing the same clade, and we here apply this model to infer divergence times in beeches (genus Fagus), using 53 fossils and nuclear sequences for all nine species. We also apply FBD dating to the fern clade Osmundaceae, with about 12 living species and 36 fossils. Fagus nuclear sequences cannot be aligned with those of other Fagaceae, and we therefore use Bayes factors to choose among alternative root positions. The crown group of Fagus is dated to 53 (62–43) Ma; divergence of the sole American species to 44 (51–39) Ma and divergence between Central European F. sylvatica and Eastern Mediterranean F. orientalis to 8.7 (20–1.8) Ma, unexpectedly old. The FBD model can accommodate fossils as sampled ancestors or as extinct or unobserved lineages; however, this makes its raw output, which shows all fossils on short or long branches, problematic to interpret. We use hand-drawn depictions and a bipartition network to illustrate the uncertain placements of fossils. Inferred speciation and extinction rates imply approximately 5× higher evolutionary turnover in Fagus than in Osmundaceae, fitting a hypothesized low turnover in plants adapted to low-nutrient conditions. This article is part of the themed issue ‘Dating species divergences using rocks and clocks’.
Article
Phylogenetic relationships among species of Quercus (oaks) from western Eurasia including the western part of the Himalayas are examined for the first time. Based on ITS and 5S–IGS data three major infrageneric groups are recognized for western Eurasia: the cerroid, iliciod, and roburoid oaks. While individuals of the cerroid and ilicoid groups cluster according to their species, particularly in the 5S–IGS analyses, individuals of species of roburoid oaks do not cluster with exception of Quercus pontica. The Cypriot endemic Quercus alnifolia belongs to the ilicoid oaks, in contrast to traditional views placing it within the cerroid oaks. Based on all ITS data available, the groups identified for western Eurasia can be integrated into a global infrageneric framework for Quercus. The Ilex group is resurrected as a well–defined group that comprises taxa traditionally placed into six subsections of Q. sects. Cerris and Lepidobalanus (white oaks) sensu Camus. Phylogenetic reconstructions suggest two major lineages within Quercus, each consisting of three infrageneric groups. Within the first lineage, the Quercus group (roburoid oaks in western Eurasia) and the Lobatae group evolved by “budding” as is reflected by incomplete lineage sorting, high variability within groups, and low differentiation among groups. The groups of the second lineage, including the Cyclobalanopsis, Cerris (cerroid oaks in western Eurasia), and Ilex (ilicoid oaks in western Eurasia) groups, evolved in a more tree–like fashion.
Article
The fagaceous genus Trigonobalanus as recently treated includes 3 species, two in Malaysia and Southeast Asia and a single species in Colombia, South America. Character analysis suggests that the genus as currently circumscribed is paraphyletic, without synapomorphies to unite the three species. Each of the three species is a morphologically distinct relict of a group that probably was ancestral to the modern genera Quercus and Fagus. Each of the three species also has at least one autapomorphy which is unique within Fagaceae. Analysis of cupule morphology in Fagaceae provides an interpretation of evolution in cupules which differs substantially from Forman's interpretation. We interpret trigonobalanoid cupules as indicative of an ancestral type of inflorescence within Fagaceae. This inflorescence type is a dichasial structure in which the outermost axes are cupular valves, but the degree of branching and subsequent number of fruits are variable. Following this model, a strict relationship exists between valve number and fruit number as seen in cupules of Trigonobalanus (valves = fruits + 1). Fossil evidence is consistent with our interpretation of the phylogenetic position of the trigonobalanoids. We propose to segregate the three species of Trigonobalanus as three monotypic genera; two of these require names which we provide here: Formanodendron and Colombobalanus.
Article
An evaluation of possible approaches to fossil oak pollen identification utilized scanning electron microscopy to examine exine-surface features of 171 collections, representing 16 Quercus subgenus Lepidobalanus species and varieties of eastern North America. Twenty qualitative pollen morphological characters were defined and tabulated for each of 217 pollen grains. The data were subjected to cluster analysis and cluster diagrams were compared with published white oak taxonomy. Pollen morphology and plant taxonomy compared well in series of the subgenus Lepidobalanus due primarily to consistency of character presence and absence within species and varieties. Pollen morphology of white oaks appears to reflect plant systematics above the species level. Use of routine SEM analysis to identify series of white oaks among fossil pollen grains likely will yield valid results.