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1. Introduction
During the Jurassic Period, several signicant geo-
logical events occurred. These events included the
fragmentation of the supercontinent Pangea, an
increase in global temperatures due to the release
of large amounts of the greenhouse gas CO2, a rise
in sea level and expansion of shallow continental
seas (Ogg et al., 2016; Button et al., 2017; Vickers et
al., 2022). Typically, this period is associated with
a warm and humid climate, which is believed to
have been caused by elevated atmospheric CO2 lev-
els (Hallam, 1985; Berner, 1994; Berner & Kothavala,
2001; Ghosh et al., 2001). Moreover, periods of cli-
mate deterioration, leading to possible glaciations
in high latitudes, have been suggested for the Ju-
rassic stages Pliensbachian, Bajocian to Bathonian,
upper Callovian to lower Oxfordian and Tithonian
(Price, 1999; Dromart et al., 2003).
Fossilised plants offer valuable insights into
plant diversity as well as palaeoclimatic, palae-
oenvironmental and palaeoecological conditions
of the past (Creber & Chaloner, 1985; Feng et al.,
2013, 2017, 2019). Palynomorphs are frequent-
ly used as proxies in palaeoclimate studies due
to their abundance in sedimentary deposits and
their close correlation with vegetation composi-
tion and climatic/environmental changes (Trav-
erse, 2007).
Researchers have documented the palaeoclimat-
ic record of the Middle Jurassic (Bajocian) relatively
well through the use of marine carbonates and or-
ganic matter proxies (O’Dogherty et al., 2006; Dera
et al., 2011; Korte et al., 2015). However, despite the
increasing availability of isotopic composition data
for fossil wood, coal and other terrestrial materials
(e.g., Hesselbo et al., 2003), it remains crucial to ex-
pand investigations into terrestrial environments
and climates. The primary aim of the present paper
is to examine the palaeoora found in Bajocian–Ba-
thonian deposits within the northern Neo-Tethys
Ocean. The current study focuses on the leaf ora
Geologos 30, 1 (2024): 33–44
https://doi.org/10.14746/logos.2024.30.1.03
The Middle Jurassic (Bajocian–Bathonian) ora
of the Tabas Block, central Iran
Saeed Maleki
Muséum National d’Histoire Naturelle, UMR 7194 Histoire naturelle de l’Homme Préhistorique, rue René Panhard,
75013 Paris, France
saeed.maleki@edu.mnhn.fr
Abstract
The present study discusses the outcome of palynlogical and palaeobotanocal investigations of Middle Jurassic strata
of the Tabas Block. The most commonly identied spore type is a trilete spore, Klukisporites, which accounts for 30 per
cent, and the genus Ischyosporites which makes up 12 per cent of the spore collection. Plant fossils recovered from the
borehole studied are indicative of a varied assemblage, starting with a diverse range of ferns and followed by Cyca-
dophytes, Ginkgophytes and Coniferophytes. The predominance of the Lowland group in the Tabas Block during the
Bajocian–Bathonian, as indicated by the Sporomorph EcoGroup (SEG) and Plant EcoGroup (PEG) models, suggests that
the strata studied were laid down mainly in a lowland environment. Dinoagellate cysts were found in locations that
correspond to river and coastal ecogroups, hinting at marine inuence.
Keywords: Sporomorph EcoGroup, Plant EcoGroup, palynology, palaeobotany, Hojedk Formation
© 2024 Maleki S. This is an open access article licensed under the Creative Commons Attribution-NonCommercial-NoDerivs License (http://
creativecommons.org/licenses/by-nc-nd/4.0/).
Saeed Maleki
TheMiddleJurassic(Bajocian–Bathonian)oraoftheTabasBlock,centralIran
34 Saeed Maleki
and palynomorphs recorded from the Hojedk For-
mation situated in the Tabas Block.
2. Geological setting
The triangular outline of the Central Iran Basin is
caused by its narrow extensions to the north-east
and north-west and its central location in the coun-
try. It is bordered by Dasht-e-Lut on the east, the
Sanandaj-Sirjan Metamorphic Belt in the south,
south-west and west, and the Alborz Mountains in
the north. The Tabas Block in the centre, the Yazd
Block in the west and the Lut Block in the east
comprise the three main parts of the Central-East
Iranian Microcontinent (CEIM; Takin, 1972). The
central structural component of the CEIM is the
Tabas Block, which was part of the Cimmerian mi-
croplate assemblage along with the adjacent base-
ment fault-bounded Lut and Yazd blocks (Stamp-
i & Borel, 2002). This microplate broke off from
Gondwana during the Permian, drifted north as the
oceanic crust of the Palaeotethys subducted north,
and nally collided with the southern edge of Eur-
asia (the Turan Plate) during the early Late Triassic
(Stocklin, 1974; Saidi et al., 1997; Stampi & Borel,
2002; Wilmsen et al., 2009).
This collision closed the Palaeotethys and
brought the Eo- and Main-Cimmerian orogenic
events in northern and central Iran to an end (Wilm-
sen et al., 2009). These tectonic events affected the
history of the Shemshak Group’s Upper Triassic
and Lower Jurassic, which included the uplift and
deformation of the foreland framework in northern
and central Iran (Fürsich et al., 2009; Wilmsen et al.,
2009; Seyed-Emami et al., 2020).
The thick Upper Triassic–Jurassic succession
in this region was divided into several formations
(Stocklin & Nabavi, 1971), which were then com-
bined into two lithostratigraphical groups: the Mid-
dle–Upper Jurassic Magu Group (northern Tabas
Block) or Bidou Group (southern Tabas Block) and
the Upper Triassic–lower Middle Jurassic Shem-
shak Group (Aghanabati, 1999).
The coal-bearing Shemshak Group (Fürsich et
al., 2009), formerly the Shemshak Formation (Car-
nian–Bajocian), was deposited in the Alborz Moun-
tains and central Iran in a foreland basin during
the early to middle Cimmerian orogeny (Agana-
bati, 1999). The Alborz Mountains, Tabas and Ker-
man regions of east-central Iran contain a number
of formations that make up the Shemshak Group
(Aganabati, 1998, Fürsich et al., 2009).
The Hojedk Formation is a thick sequence of
coal-bearing terrigenous sedimentary rocks that
overlie the marine Badamu Formation (Seyed-
Emami et al., 2004). The Stratigraphic Names Com-
mittee of Iran named the Hojedk Formation in 1964
(Stöcklin & Setudehnia, 1971). The fossiliferous coal
horizons yield a well-preserved leaf ora. Accord-
ing to Lasemi & Kheradmand (1999), the strata of the
Hojedk Formation were laid down in a river-dom-
inated, fault-controlled delta and meandering river
system. Therefore, this formation is comparable in
time to the coal-bearing Dansirit Formation in the
southern Alborz, which is also marginally marine
and deltaic (Fürsich et al., 2009). Both formations
indicate a distinct shallowing of the depositional
environments in northern and eastern central Iran
prior to the Mid-Cimmerian tectonic event (Fürsich
et al., 2009). Based on ammonite records for both
underlying and overlying units (Badamu & Parva-
deh formations, respectively) (Seyed-Emami et al.,
2020) and plant macrofossils (Badihagh et al., 2019),
the Hojedk Formation is generally dated as late Ba-
jocian to early Bathonian (Badihagh et al., 2019).
3. Previous studies
Various researchers have explored plant micro-
(Kimiyai, 1968; Arjang, 1975; Ashraf, 1977; Achil-
les et al., 1984) and macrofossils (Schweitzer, 1978;
Schweitzer et al., 1997) from the Middle Jurassic in
Iran and Afghanistan. Several fossils of bryophytes,
lycophytes, equisetales and ferns were reported by
Schweitzer (1978) and Schweitzer et al. (1997). In
addition to this material, plant remains assignable
to Caytoniales, Cycadophytes, Bennettites, Ginkgo-
phytes, Czekanowskiales and Coniferales have also
been documented from Middle Jurassic deposits in
Iran (Barnard & Miller, 1976; Schweitzer & Kirch-
ner, 1995, 1996, 1998, 2003; Schweitzer et al., 2000).
Compared to leaf oras, fossil woods are infre-
quently found. Cupressinoxylon (Seward, 1912) and
Mesembrioxylon sp. (Sitholey, 1940; Jacob & Shukla,
1955) have been recorded from the Saighan Series
of northern Afghanistan. Poole & Ataabadi (2005)
documented the discovery of conifer woods from
the Hojedk Formation in Iran.
Mesozoic deposits extending from central Iran
northwards and eastwards into Afghanistan contain
well-preserved oras. These Mesozoic plant-bear-
ing deposits are crucial because they form a contin-
uous series from the Norian to the Middle Juras-
sic (Schweitzer et al., 1997). The fossils originate
from mining areas in northern and central Iran and
north-east Afghanistan (Schweitzer et al., 2000).
A few studies explored the Middle Jurassic ora
of Iran in the rst half of the twentieth century (Tip-
TheMiddleJurassic(Bajocian–Bathonian)oraoftheTabasBlock,centralIran 35
per, 1921). However, the second half of that century
played a crucial role in uncovering the history of
micro- and macrooral investigations in the Central
Iran Basin (Huckriede et al., 1962; Assereto et al.,
1968; Corsin & Stampi, 1977; Fakhr, 1977). After
Assereto (1966) had dened the Shemshak Forma-
tion, many authors studied this and recorded dif-
ferent species of Neocalamites.
Kilpper (1964) and Barnard (1965) reported sphe-
nophytes from the Shemshak Formation of the Al-
borz Mountains in northern Iran. Schweitzer et al.
(1997) revised the Jurassic ora of Iran in detail, ac-
counting for all previously described species. The
lower Mesozoic strata (Norian–Rhaetian) in Kerman
in the Central Iran Basin have yielded remains of Ne-
ocalamites (Assereto et al., 1968; Corsin & Stampi,
1977; Fakhr, 1977). However, most of the specimens
examined were either too small or poorly preserved
to be identied accurately (Schweitzer et al., 1997).
4. Material and methods
A borehole located in the Mazino Coal Mine (Fig. 1)
on the Tabas Block was selected to investigate the pal-
ynology and palaeobotany of the Hojedk Formation.
Previous studies have recorded that the formation
was of Bathonian–Bajocian age, based on its strati-
graphical characteristics and fossil content (Ameri et
al., 2013; Ameri, 2018; Badihagh et al., 2019).
4.1. Microfossils
A palynological analysis was performed on 60 sam-
ples. Standard palynological processing techniques,
which involve acid digestion (Traverse, 2007), were
used to create the palynology slides. A Leitz Wet-
zlar microscope was used to examine the materi-
al, and photographs were captured using a Sony
DSC-W530 digital camera. For each sample, the fre-
quency of spores, pollen grains, dinoagellate cysts
and sedimentary organic matter were determined
by counting. The SEG model (Abbink, 1998; Abbink
et al., 2004) was employed to examine the palaeo-
climate and palaeoenvironment of the Bajocian–Ba-
thonian deposits in the intervals studied.
4.2. Macrofossils
Several specimens were collected from the Hojedk
Formation on the Tabas Block. During the extrac-
tion of material, stratigraphical control was main-
tained at each sample site. The samples obtained
for this research range in size from 100 to 500 mm
in length and width. All plant identications were
made by direct observation using a dissecting mi-
croscope, with oblique lighting to emphasise details
of the fossil leaves. Following cleansing, the speci-
mens were photographed under a low-angle inci-
dental light using an Olympus E-500 camera.
Various studies were consulted to identify the
leaves, leaets and reproductive organs of Bennet-
titales, Caytoniales, Coniferales and ferns (Harris,
1964; Watson & Sincok, 1992). The macrofossils
were quantitatively analysed by counting each
identiable plant fragment on both sides of the
rock slabs. These plant fossils were then associat-
ed with their respective presumed environments,
known as PEG, by considering literature data and
morphological characters. This approach allowed
Fig. 1. Locality map showing the borehole studied within the Mazino Coal Mine.
36 Saeed Maleki
for identifying variations in plant composition and
distribution between different environments and
provided valuable insights into the palaeoecology
of the study area.
5. Results
5.1. Microoral assemblage
The palynomorphs present in the interval studied
on the Tabas Block exhibit poor preservation, and
numerous specimens are too degraded to permit
identication. The predominant identied type is
trilete spores, with the genera Klukisporites com-
prising 30 per cent and Ischyosporites 12 per cent of
the spore assemblage, respectively. The presence of
dinoagellate cysts in the Hojedk Formation indi-
cates a brief period of marine inuence during dep-
osition. The genus Cribroperidinium was the most
abundant of dinoagellate cysts found in the bore-
hole studied. Alisporites, Araucariacites and Chas-
matosporites were the most often observed pollen
genera in this borehole in the Mazino mining area
(Fig. 2A). A selected number of recorded palyno-
morphs is shown in Figure 3.
5.1.1. Sporomorphs Ecogroup (SEG) model
The SEG model utilises palynology to reconstruct the
palaeoclimate in shallow environments during the
Late Jurassic period, as demonstrated in studies such
as Abbink (1998) and Abbink et al. (2004). The spore
and pollen grains present on the Tabas Block have
been categorised into four SEGs. Table 1 and Figure
2B provide detailed data sets for the SEGs identied
in the intervals studied. Table 1 also classies all the
identied spores and pollen grains based on their
parent plant habitats. Ferns constitute the predomi-
nant genera identied in the borehole studied. Addi-
tionally, species belonging to Lycophyta, Bryophyta
and Coniferophyta have been observed.
The SEG data obtained from the Tabas Block
exhibit a signicant increase in ‘lowland’ elements
during the Bajocian–Bathonian. This EcoGroup is
typically associated with lowland areas. The SEG
data presented in Figure 2B and Table 1 indicate
the inuence of coastal, tidal and river vegetation
on the prevalence of the dominant lowland group
throughout the rock unit.
Fig. 2. Pie chart illustrating the frequency distribution of: A – Palynomorphs; B – SEG; C – Plant fossils; D – PEG record-
ed within the Hojedk Formation in the present study.
TheMiddleJurassic(Bajocian–Bathonian)oraoftheTabasBlock,centralIran 37
5.2. Macrooral assemblage
The borehole studied shows a diverse range of
ferns, including Cladophlebis, Coniopteris, Feriziano-
pteris, Todites, Klukia and Marattia. Cycadophytes,
such as Ptilophyllum, Taeniopteris, Anomozamites
and Nilssonia, were also found, as well as only two
types of Ginkgophytes, namely Sphenobaiera and
Ginkgoites. Coniferophytes, such as Elatocladus and
Podozamites, were also observed (Fig. 2C). A select-
ed number of recorded plant fossils is presented in
Figure 4.
Table 1. Attributions of the palynological assemblage to main plant groups and to sporomorph ecogroups.
SEG Sporomorph
genera Known or probable parent plant afnity Climatic
indicator
Lowland
Chasmatosporites Ginkgophyta/Cycadophyta Drier, cooler
Cyathidites Pterophyta (Cyatheaceae, Dipteridaceae, Dicksoniaceae) Warmer, wetter
Deltoidospora Pterophyta (Cyatheaceae, Dipteridaceae, Dicksoniaceae) Drier, warmer
Dictyophyllidites Pterophyta (Dipteridaceae, Dicksoniaceae, Cyatheaceae, Matoniaceae) Warmer, wetter
Gleicheniidites Pterophyta (Gleicheniaceae) Warmer, wetter
Ischyosporites Pterophyta (Schizaeaceae) Warmer, wetter
Klukisporites Pterophyta (Schizaeaceae) Warmer, wetter
Osmundacidites Pterophyta (Osmundaceae, Marattiaceae) Wetter
Sellaspora Pterophyta/Pteridophyta Warmer, wetter
Striatella Pterophyta (Pteridaceae) Warmer, wetter
Coastal Araucariacites Coniferophyta (Araucariaceae) Drier, cooler
River Annulispora Bryophyta (Sphagnaceae) Wetter
Tidally-in-
uenced
Alisporites Pteridospermophyta (Corystospermaceae) Warmer, drier
Retitriletes Lycophyta (Lycopodium) Warmer, wetter
Fig. 3. Selected palynomorphs from the study interval on the Tabas Block (scale bar equals 20 μm). A – Cyathidites aus-
tralis Couper, 1953; B – Cyathidites minor Couper, 1953; C – Deltoidospora hallii Miner, 1935; D, E – Dictyophyllidites
mortonii (de Jersey) Playford & Dettmann, 1965; F – Osmundacidites wellmanii Couper, 1953; G-I – Klukisporites varieg-
atus Couper, 1958; J, K – Gleicheniidites senonicus Ross emend. Skarby, 1964; L – Alisporites australis de Jersey, 1962;
M – Alisporites lowoodensis de Jersey, 1963; N – Araucariacites australis Cookson ex Couper, 1953; O – Gonyaulacysta
jurassica (Deandre) Norris & Sarjeant, 1965.
38 Saeed Maleki
5.2.1. PEG model
To gain insight into the palaeoecology of the
study area, the macrofossils were categorised into
different PEG based on their environmental re-
quirements, following the approach proposed by
Abbink (Abbink, 1998; Abbink et al., 2004) for spo-
romorphs. This classication system, as described
by Costamagna et al. (2017), has helped group the
macroplant fossils into distinct ecogroups based on
their ecological needs. This approach offers a bet-
ter understanding of the palaeoecology of the study
area and the environmental factors that shaped
the distribution of different plant species during
the Middle Jurassic. The PEG model (Table 2; Fig.
Fig. 4. Selected plant fossils from the study area (scale bar equals 10 mm). A – Sphenobaiera longifolia (Pomel) Florin,
1936; B – Nilssonia sarakhs Barnard & Miller, 1976; C – Todites williamsoni (Brongniart) Seward, 1900; D – Klukia exilis
(Philips) Raciborski emend. Harris, 1961; E – Coniopteris hymenophylloides Seward, 1990; F – Cladophlebis sp; G – Cl-
adophlebis denticulata (Brongniart) Fontaine, 1889; H – Marattia intermedia (Münsters) Kilpper, 1964.
TheMiddleJurassic(Bajocian–Bathonian)oraoftheTabasBlock,centralIran 39
2D) helped differentiate the macroplant fossils into
different ecogroups based on their respective eco-
logical requirements. In the Middle Jurassic of the
Tabas Block, four distinct plant ecogroups were
identied: the River PEG, the humid Lowland PEG,
the dry Lowland PEG and the Coastal/Tidally in-
uenced PEG.
6. Discussion
During the Jurassic Period, conifers were the prev-
alent forest trees across the ancient world, and it
was during this time that most modern conifer fam-
ilies originated and diversied (Miller, 1977, 1982;
Stewart & Rothwell, 1993; Leslie et al., 2012). De-
spite their critical role in Jurassic environments, our
current knowledge of the palaeobiology and pal-
aeoecology of conifer species is limited, given the
scarcity and incompleteness of the Jurassic record.
Various studies, including those by Vakhrameev et
al. (1970), Vakhrameev (1991), Wang et al. (2005)
and Falcon-Lang et al. (2009), have suggested that
during the Mesozoic era conifers typically thrived
on slopes that were relatively dry and well drained
in upland forests. Nonetheless, it is worth noting
that not all conifer species were conned solely to
these drier habitats.
In general, ferns thrive in environments that
are shaded and humid and that have moderate to
warm temperatures. However, not all fern species
are limited to these specic conditions (Abbink et
al., 2004; Van Konijnenburg-van Cittert, 2002). Most
extant ferns tend to thrive in humid environments,
whether in tropical or temperate regions – although,
as mentioned before, they can also survive in drier
habitats. Because ferns that live in warm and hu-
mid environments are more common, their spores
are commonly used as indicators of humidity levels
(Harris, 1961; Van Konijnenburg-van Cittert & van
der Burgh, 1989).
Cycadophytes, encompassing Cycadales and
Bennettitales, are gymnosperms of an ancient lin-
eage dating back to the Palaeozoic era (Brenner et
al., 2003; Condamine et al., 2015). Among macrore-
mains available, the genera Nilssonia, Anomozamites,
Taeniopteris, and Ptilophyllum are classied as mem-
bers of this group. According to Abbink’s research
in 1998, Matoniaceae (Deltoidospora) tends to thrive
under warm, dry conditions. Pollen of Araucari-
acites is associated with the family Araucariaceae
(Tralau, 1967; Boulter & Windle, 1993). A signi-
cant presence of these pollen grains during the Ju-
rassic Period is linked to warm climatic conditions,
as Mohr (1989) indicated. Alisporites has been linked
to the Corystospermales group because of the dis-
covery of its pollen grains within Pachypteris-type
plants. This association suggests that Alisporites
existed in drier lowland environments, consistent
with the known habitats of the Corystospermales.
6.1. Palaeoenvironment and palaeoclimate
The ndings obtained from both the SEG and PEG
models are consistent with each other, with the
Lowland group being the dominant category in
both models (Fig. 2). The river and coastal groups
identied in both PEG and SEG analyses are locat-
ed precisely where dinoagellate cysts have been
found. In other words, the sedimentary strata in
the Tabas Block were predominantly deposited in
a lowland environment with the presence of marine
inuences.
According to Schweitzer et al. (1997), during the
Middle Jurassic period, the deposits in the western
and northern regions of Alborz were exclusive-
ly terrestrial. However, in the central and eastern
parts of Alborz, as well as in the Kerman Basin to
the south, there were sporadic occurrences of ma-
rine intercalations within the deposits.
During the Middle Jurassic, Iran was situated
within Vakhrameev’s Euro-Sinian Region (Vaez-Ja-
vadi, 2018). This region was characterised by warm
and humid climatic conditions from the Late Trias-
sic to the Middle Jurassic (Vakhrameev, 1991). The
Table 2. Attributions of plant fossils to main groups and
to sporomorph ecogroups.
PEG Genus Plant Group Climatic
indicator
Lowland
Cladophlebis Ferns Wetter
Coniopteris Ferns Wetter
Ferizianopteris Ferns Wetter
Ptilophyllum Cycadophytes Drier
Taeniopteris Cycadophytes Drier
Todites Ferns Wetter
Anomozamites Cycadophytes Drier
Klukia Ferns Warmer,
wetter
Marattia Ferns Warmer,
wetter
Nilssonia Cycadophytes Drier
Coastal
Sphenobaiera Ginkgophytes Warmer,
wetter
Ginkgoites Ginkgophytes Warmer,
wetter
River Elatocladus Coniferophytes Drier
Upland Podozamites Coniferophytes Cooler
40 Saeed Maleki
palynological and palaeobotanical data obtained
from the borehole studied also support the notion
of a generally warm and humid climate during the
Bathonian-Bajocian. Tables 1 and 2 show that most
of the recorded species are indicative of a warmer
and wetter climate. The results of the palaeoclimate
analysis based on both palynology and palaeobota-
ny are in agreement with each other.
6.2. Comparison and correlation
Ameri et al. (2013) identied gymnosperm and
pteridophyte plant fossils from the Hojedk Forma-
tion in Kerman (Iran), suggesting that the deposi-
tion of the formation occurred under subtropical
conditions. Ameri (2018) focused on plant fossils
from the same formation but in a different location
and identied 13 species, in seven genera, of macro
plant fossils, including gymnosperm and pterido-
phyte groups, dating back to the Bajocian–Bathoni-
an. These ndings provided further insight into the
ora of Iran during this Jurassic; however, the plant
species documented in the current study exhibited
a greater diversity in comparision to those previ-
ously reported by Ameri (2018).
In their study, Badihagh et al. (2019) examined
the palynological and palaeobotanical aspects of the
Hojedk Formation. The presence of minor marine
palynomorphs, such as proximate dinoagellate
cysts, suggests a transgression in their studied in-
terval. The palynological assemblages found in the
Hojedk Formation indicated a diverse range of par-
ent ora, with ferns, bryophytes and gymnosperms
(including mainly conifers and ginkgophytes) being
the most prevalent in descending quantitative order
(Badihagh et al., 2019). By comparing these parent
oras with modern plant ecology, those researchers
concluded that these palynomorphs accumulated
in a moist, warm climate during the Middle Juras-
sic. Additionally, a comparison of the parent plants
with previous palaeooristic studies revealed that
the Tabas Block was located in the mid-Asian por-
tion of the Indo-European oristic province of the
Northern Hemisphere. In line with the research
conducted by Badihagh et al. (2019), a minor (3 per
cent) presence of dinoagellate cysts in the Hojedk
formation was identied in the current study. How-
ever, the diversity of spores and pollen grains was
found to be greater in the present study.
Vaez-Javadi & Mirzaei-Ataabadi (2006) con-
ducted a study on Jurassic plant macrofossils from
the Hojedk Formation in east-central Iran, which
suggested that the formation was of Bajocian–Ba-
thonian age. Those researchers also found evidence
of a uniform palaeoclimate and environment in
Iran during this time, which is consistent with the
ndings of Vaez-Javadi’s later studies on Middle
Jurassic ora and palynology in Iran (Vaez-Javadi,
2018, 2019). In her 2018 study, Vaez-Javadi focused
on the Hojedk Formation in south Kouchekali, the
south-western area of Tabas City, and found that
the relative abundance of certain plant groups sug-
gested a humid subtropical climate for that locality.
The ndings also conrmed a uniform palaeocli-
mate and vegetation cover in Iran during the Mid-
dle Jurassic period. In 2019, Vaez-Javadi conducted
a study on the Middle Jurassic palynology of the
southwest Tabas Block in central-east Iran, which
showed an abundance of ferns and cycadophytes
as parent oras, indicating a moist, warm climate
during the early Middle Jurassic. The ndings also
revealed that the region comprised several environ-
ments, including upland, warmer lowland, wetter
lowland, rivers and a delta. Consistent with previ-
ous studies, the palaeovegetation observed in the
present study suggests a subtropical climate. Simi-
lar to the research conducted by Vaez-Javadi (2019),
ferns also contributed signicantly to the palaeo-
vegetation observed in the current study.
China has been the subject of several investiga-
tions that have focused on palaeovegetation of Mid-
dle Jurassic age. Palynomorphs present in the Tarim
Basin located in north-west China were studied by
Jiang et al. (2008), during which they detected spe-
cic miospores such as Callialasporites dampieri, Cy-
athidites australis, Dictyophyllidites harrisii, Klukispo-
rites variegatus and Osmundacidites wellmanii. In the
current study, Klukisporites variegatus was identied
as the most abundant palynomorph, representing
a signicant proportion of miospores identied.
Additionally, other miospores previously found
in China were detected in the current study for the
study area. Sun et al. (2010) conducted a study on
the strata and oras of the Junggar Basin in Xinjiang,
north-west China, of Late Triassic to Middle Juras-
sic age. The Late Triassic to early Middle Jurassic
oras from the basin were found to consist of four
oristic assemblages. The Neocalamites–Marattiop-
sis assemblage (Ass. III, Early Jurassic) and the Co-
niopteris–Raphaelia assemblage (Ass. IV, Middle
Jurassic) are part of the early Middle Jurassic “Sibe-
rian ora” (continental oristic province). Certain
species that were identied in Sun et al.’s (2010)
study were also identied in the present study. In
a study conducted by Zhang et al. (2021), the paly-
noora and palaeoclimate of the late Early Jurassic
in eastern Liaoning, China, were investigated. The
palynoora in the upper part of the Changliangzi
Formation were found to be dominated by pterido-
TheMiddleJurassic(Bajocian–Bathonian)oraoftheTabasBlock,centralIran 41
phyte spores (64.01 per cent, on average) and gym-
nosperm pollen grains (34.99 per cent, on average),
while bryophyte spores made up less than 1 per cent
of the total palynoora. The dominant component
of this palynoora alternates between pteridophyte
spores and gymnosperm pollen, indicating a varied
environment during the late Early Jurassic in east-
ern Liaoning, China. The present study conducted
in Iran and that by Zhang et al. (2021) in eastern
Liaoning, China, indicate a signicant and similar
dominance of pteridophyte spores. This suggests
a parallel pattern of prevalence for this group in
both regions.
The research conducted by Stukins et al. (2013)
focused on the Middle Jurassic period (Lajas For-
mation) in the Neuquén Basin of Argentina. Based
on the presence of commonly occurring taxa such as
Deltoidospora, Araucariacites australis and Callialaspo-
rites spp., their study could only establish a par-
tial correlation with the palynoora of the Hojedk
Formation. The palynoora observed in the north-
ern region of Argentina was the focus of research
by Volkheimer et al. (2008). Their study identied
the presence of certain miospores from the Trias-
sic–Middle Jurassic, including Araucariacites, Cal-
lialasporites and Dictyophyllidites, which were also
identied in the present study.
In an effort to reconstruct vegetation and eval-
uate potential dinosaur-plant interactions, Slater et
al. (2018) carried out a study on spores and pollen
from the Middle Jurassic Ravenscar Group in north-
ern Yorkshire, England. In that study, several taxa
in common were identied, including Deltoidospora
spp., Dictyophyllidites harrisii, Araucariacites austra-
lis, Cycadopites spp. and Callialasporites spp. In the
present study, the miospores identied in a study
by Slater et al. (2018) were also found in the Hojedk
Formation.
7. Conclusions
The present study discusses the results of a palyno-
logical and palaeobotanical analysis of Middle Ju-
rassic strata present on the Tabas Block. Both SEG
and PEG models suggest that the Lowland group
was the dominant category during the Bajocian
in the Tabas Basin. The river, coastal and upland
groups identied in both models correspond to the
locations where dinoagellate cysts were found.
This indicates that while marine inuences were
present during this time, the sedimentary strata
were laid down mainly in a lowland environment.
Acknowledgements
The author expresses his gratitude to Dr Shreya
Mishra and an anonymous reviewer for their valu-
able and constructive comments.
References
Abbink, O.A., 1998. Palynological investigations in the Juras-
sic of the North Sea region. Utrecht: PhD thesis, Univer-
sity of Utrecht, 192 pp.
Abbink, O., Van Konijnenburg-van Cittert, J.H.A. & Viss-
cher, H., 2004. A sporomorph ecogroup model of the
Northwest European Jurassic–Lower Cretaceous:
concepts and framework. Geologie en Mijnbouw 83,
17–38.
Achilles, H., Kaiser, H., Schweitzer, H.J., 1984. Die rä-
to-jurassischen Floren des Iran und Afghanistans:
7. Die Mikroora der obertriassisch-jurassischen
Ablagerungen des Alborz-Gebirges (Nord Iran). Pal-
aeontographica B 194, 14–95.
Aghanabati, A., 1999. Jurassic stratigraphy of Iran, vol. 1.
Geological Survey of Iran, Tehran, 356 pp. [in Per-
sian].
Ameri, H., 2018. The Bajocian–Bathonian plant fossil
from the Hojedk formation, Lenjan section, Kerman,
Iran. Arabian Journal of Geosciences 11, https://doi.
org/10.1007/s12517-017-3339-8
Ameri, H., Dastanpour, M., Khalilizade, H. & Zamani, F.,
2013. Plant fossil remains from the Bajocian–Bathoni-
an of Hojedk Formation, Babhutk area, Kerman, Iran.
Arabian Journal of Geosciences 7, 2293–2302, https://
doi.org/10.1007/s12517-013-0878-5
Arjang, B., 1975. Die räto-jurassischen Floren des Iran und
Afghanistans: 1. Die Mikroora der räto-jurassischen
Ablagerungen des Kermaner Beckens (Zentral-Iran).
Palaeontographica B, 152, 85–114.
Ashraf, A.R., 1977. Die räto-jurassischen Floren des Iran
und Afghanistans. 3. Die Mikrooren deren der rä-
tischen bis unter-kretazischen Ablagerungen Nord
Afghanistans. Palaeontographica Abteilung B 161, 1–97.
Assereto, R., 1966. The Jurassic Shemshak Formation in
Central Alborz (Iran). Rivista Italiana di Paleontologia e
Stratigraa 72, 1133—1182.
Assereto, R., Riccardo, P. & Sestini, N.F., 1968. Jurassic
stratigraphy of central Alburz (Iran). Rivista Italiana di
PaleontologiaeStratigraa 74, 3–21.
Badihagh, M.T., Sajjadi, F., Farmani, T. & Uhl, D., 2019.
Middle Jurassic palaeoenvironment and palaeobioge-
ography of the Tabas Block, Central Iran: palynologi-
cal and palaeobotanical investigations. Palaeobiodiver-
sity and Palaeoenvironments 99, 379–399.
Barnard, P.D.W., 1965. The geology of the upper Djadjer-
ud and Lar valleys (North Iran) II. Palaeontology. Flo-
ra of the Shemshak formation 1. Liassic plants from
Dorud. RivistaItalianadiPaleontologiaeStratigraa 71,
1123–1168.
Barnard, P.D.W. & Miller, J.C., 1976. Flora of the Shem-
shak Formation (Elbourz, Iran). Part 3. Middle Juras-
42 Saeed Maleki
sic (Dogger) plants from Katumbargah, Vasek Gah
and Imam Manak. Palaeontographica B, 155, 31–117.
Berner, R.A., 1994. GEOCARB II: a revised model of at-
mospheric CO2 over Phanerozoic time. American Jour-
nal of Science 294, 56–91.
Berner, R. A., & Kothavala, Z., 2001. GEOCARB III: a re-
vised model of atmospheric CO2 over Phanerozoic
time. American Journal of Science 301, 182–204.
Boulter, M.C. & Windle, T., 1993. A reconstruction of
some Middle Jurassic vegetation in Northern Europe.
Special Papers in Palaeontology 49, 125–154.
Brenner, E.D., Stevenson, D.W. & Twigg, R.W., 2003.
Cycads: evolutionary innovations and the role
of plant-derived neurotoxins. Trends in Plant Sci-
ence 8, 446–452. https://doi.org/10.1016/S1360-
1385(03)00190-0
Button, D.J., Lloyd, G.T., Ezcurra, M.D., Richard, J. &
Butler, R.J., 2017. Mass extinctions drove increased
global faunal cosmopolitanism on the supercontinent
Pangaea. Nature Communications 8, 733, doi: 10.1038/
s41467-017-00827-7.
Condamine, F.L., Nagalingum, N.S., Marshall, C.R. &
Morlon, H., 2015. Origin and diversication of living
cycads: a cautionary tale on the impact of the branch-
ing process prior in Bayesian molecular dating. BMC
Evolutionary Biology 15, 1–18.
Corsin, P. & Stampi, M.G., 1977. La formation de Shem-
shak dans l’Elburz oriental (Iran) ore – stratigraphie
– paléogéographie. Geobios 10, 509–571.
Costamagna, L.G., Kustatscher, E., Scanu, G.G., Del Rio,
M., Pittau, P. & Van Konijnenburg-Van Cittert, J.H.,
2017. A palaeoenvironmental reconstruction of the
Middle Jurassic of Sardinia (Italy) based on integrated
palaeobotanical, palynological and lithofacies data as-
sessment. Palaeobiodiversity and Palaeoenvironments 98,
111–138, https://doi.org/10.1007/s12549-017-0306-z
Creber, G.T. & Chaloner,W.G., 1985. Tree growth in the
Mesozoic and Early Tertiary and the reconstruction
of palaeoclimates. Palaeogeography, Palaeoclimatology,
Palaeoecology 52, 35–59.
Dera, G., Brigaud, B., Monna, G., Laffont, R., Pucéat, E.,
Deconinck, J.-F., Pellenard, P., Joachimski, M.M. &
Durlet, C., 2011. Climatic ups and downs in a dis-
turbed Jurassic world. Geology 39, 215–218.
Dromart, G., Garcia, J.-P., Gaumet, F., Picard, S., Rous-
seau, M., Atrops, F., Lécuyer, C. & Sheppard, S.M.F.,
2003. Perturbation of the carbon cycle at the Middle/
Late Jurassic transition: Geological and geochemical
evidence. American Journal of Science 303, 667–707.
Fakhr, M.S., 1977. Flore jurassique de l’Iran. Contribution
a l’étude de la ore Rhéto Liasique de la formation de
Shemshak de l’Elbourz (Iran). Mémoires de la section
des Sciences de Paris 5, 1–178.
Falcon-Lang, H.J., Nelson, W.J., Elricks, S., Looy, C.V.,
Ames, P.R. & DiMichele, W.A., 2009. Incised channel
lls containing conifers indicate that seasonally dry
vegetation dominated Pennsylvanian tropical low-
lands. Geology 37, 923–926.
Feng, Z., Wang, J., Rößler, R., Hans, K. & Wei, H.B., 2013.
Complete tylosis formation in a latest Permian conifer
stem. Annals of Botany 111, 1075–1081.
Feng, Z., Wang, J., Rößler, R., Ślipiński, A. & Labandeira,
C., 2017. Late Permian wood-boring reveals an intri-
cate network of ecological relationships. Nature Com-
munications 8, 556.
Feng, Z., Bertling, M., Noll, R., Ślipiński, A. & Rößler,
R., 2019. Beetle borings in wood with host response
in early Permian conifers from Germany. PalZ 93,
409–421.
Fürsich, F.T., Wilmsen, M., Seyed-Emami, K. & Majidi-
fard, M.R., 2009. The Mid-Cimmerian tectonic event
(Bajocian) in the Alborz Mountains, Northern Iran:
evidence of the break-up unconformity of the South
Caspian Basin. Geological Society London, Special Publi-
cations 312, 189–203.
Ghosh, P., Ghosh, P. & Bhattacharya, S.K., 2001. CO2 lev-
els in the Late Paleozoic and Mesozoic atmosphere
from soil carbonate and organic matter, Satpura ba-
sin, Central India. Palaeogeography, Palaeoclimatology,
Palaeoecology 170, 219–236.
Hallam, A., 1985. A review of Mesozoic climates. Journal
of the Geological Society (London) 142, 433–445.
Harris, T.M., 1961. The Yorkshire Jurassic Flora. I Thalophyta
–Pteridophyta. Trustees of the British Museum (Natu-
ral History), London, 212 pp.
Harris, T.M., 1964. The Yorkshire Jurassic Flora II Caytoni-
ales, Cycadales & Pteridospermas. Trustees of the British
Museum (Natural History), London, 214 pp.
Hesselbo, S.P., Morgans-Bell, H.S., McElwain, J.C., Rees,
P.M., Robinson, S.A. & Ross, C.E., 2003. Carbon-cycle
perturbation in the Middle Jurassic and accompany-
ing changes in the terrestrial paleoenvironment. Jour-
nal of Geology 111, 259–276.
Huckriede, R., Kürsten, M. & Venzlaff, H., 1962. Zur Ge-
ologie des Gebietes zwischen Kerman und Sagand.
Neues Jahrbuch für Geologie und Paläontologie 81, 237–
276.
Jacob, K. & Shukla, B.N., 1955. Jurassic plants from the
Saighan series of northern Afghanistan and their pale-
oclimatic and paleogeographic signicance. Memoirs
of the Geological Survey of India, Palaeontologia Indica 33,
1–64.
Jiang, D.X., Wang, Y.D., Robbins, E.I., Wei, J. & Tian, N.,
2008. Mesozoic non-marine petroleum source rocks
determined by palynomorphs in the Tarim Basin,
Xinjiang, Northwestern China. Geological Magazine
145, 868–885.
Kilpper, K., 1964. Über eine Rät/ Lias–Flora aus dem
nördlichen Abfall des Alburs–Gebirges in Nordiran.
1. Bryophyta und Pteridophyta. Palaeontographica
Abteilung B, 114, 1–78.
Kimiyai, A., 1968. Jurassic plant microfossils from the
Kerman region. Bulletin of the Iranian Petroleum Insti-
tute 33, 91–111.
Korte, C., Hesselbo, S.P., Ullmann, C.V., Dietl, G., Ruhl,
M., Schweriert, G. & Thibault, N., 2015. Jurassic cli-
mate mode governed by ocean gateway. Nature Com-
munications 6, 10015.
Lasemi, Y. & Kheradmand, A., 1999. Facies, sedimentary
environment and origin of sandstones of Hojedk Formation
in a strict-structure fault controlled basin of Zarand area,
TheMiddleJurassic(Bajocian–Bathonian)oraoftheTabasBlock,centralIran 43
Kerman. Proceeding of the 3rd Symposium of Geologi-
cal Society of Iran, Tehran, 549–552.
Leslie, A.B., Beaulieu, J.M., Rai, H.S., Crane, P.R., Dono-
ghue, M.J. & Mathews, S., 2012. Hemisphere-scale
differences in conifer evolutionary dynamics. Pro-
ceedings of the National Academy of Sciences of the United
States of America 109, 16217–16221.
Miller, C.N., 1977. Mesozoic conifers. Botanical Review 43,
217–280.
Miller, C.N., 1982. Current status of Paleozoic and Meso-
zoic conifers. Review of Palaeobotany and Palynology 37,
99–114.
Mohr, B.A., 1989. New palynological information on the
age and environment of Late Jurassic and Early Cre-
taceous vertebrate localities of the Iberian Peninsula
(eastern Spain and Portugal). Berliner Geowissenschaft-
lichen Abhandlungen, Reihe A 106, 291–301.
O’Dogherty, L.O., Sandoval, J., Bartolini, A., Bruchez, S.,
Bill, M. & Guex, J., 2006. Carbon isotope stratigraphy
and ammonite faunal turnover for the Middle Jurassic
in the Southern Iberian palaeomargin. Palaeogeogra-
phy, Palaeoclimatology, Palaeoecology 239, 311–333.
Ogg, J.G., Ogg, G.M. & Gradstein, F.M., 2016. Jurassic.
[In:] Ogg, J.G., Ogg, G.M. & Gradstein, F.M. (Eds):
A Concise Geologic Time Scale. Elsevier, Amsterdam,
pp. 151–166.
Poole, I., & Ataabadi, M.M., 2005. Conifer woods of the
Middle Jurassic Hojedk Formation (Kerman basin)
Central Iran. IAWA Journal 26, 489–505.
Price, G.D., 1999. The evidence and implications of po-
lar ice during the Mesozoic. Earth-Science Reviews 48,
183–210.
Saidi, A., Brunet, M-F.& Ricou, L-E., 1997. Continental ac-
cretion of the Iran Block to Eurasia as seen from Late
Paleozoic to Early Cretaceous subsidence curves. Geo-
dinamica Acta 10, 189–208.
Schweitzer, H.J., 1978. Die Räto-Jurassischen Floren des
Iran und Afghanistans: 5, Todites princeps, Thau-
matopteris brauniana und Phlebopteris polypodi-
oides. Paleontographica B, 168, 17–60.
Schweitzer, H.J. & Kirchner, M., 1995. Die Räto-Juras-
sischen Floren des Iran und Afghanistans: 8, Ginkgo-
phyta. Paleontographica B, 237, 1–58.
Schweitzer, H.J. & Kirchner, M., 1996. Die Räto-Juras-
sischen Floren des Iran und Afghanistans: 9, Conif-
erophyta. Paleontographica B, 238, 77–139.
Schweitzer, H.J. & Kirchner, M., 1998. Die Räto-Juras-
sischen Floren des Iran und Afghanistans: 11, Pteri-
dospermophyta und Cycadophyta I: Cycadales. Pal-
aeontographica B, 248, 1–85.
Schweitzer, H.J. & Kirchner, M., 2003. Die Räto-Juras-
sischen Floren des Iran und Afghanistans. 13. Cyc-
adophyta III: Bennettitales. Palaeontographica B, 264,
1–166.
Schweitzer, H.J., van Konijnenburg-van Cittert, J.H.A. &
van der Burgh, J., 1997. The Räto-Jurassic ora of Iran
and Afghanistan. 10: Bryophyta, Lycophyta, Sphe-
nophyta-Eusporangiatae. Palaeontographica B, 243,
103–192.
Schweitzer, H.J., Kirchner, M. & van Konijnenburg-van
Cittert, J.H.A., 2000. The Räto-Jurassic ora of Iran
and Afghanistan. 12: Cycadophyta II: Nilssoni-
ales. Palaeontographica B, 254, 1–63.
Seward, A.C., 1912. Mesozoic plants from Afghanistan
and Afghan-Turkistan. Memoirs of the Geological Sur-
vey of India, Palaeontologia Indica 4, 1–57.
Seyed-Emami, K., Fürsich, F.T. & Wilmsen, M., 2004.
Documentation and signicance of tectonic events in
the northern Tabas block (east-central Iran) during
the Middle and Late Jurassic. Rivista Italiana di Paleon-
tologiaeStratigraa 110, 167–171.
Seyed-Emami, K., Wilmsen, M. & Fürsich, F.T., 2020.
A summary of the Jurassic system in north and
East-Central Iran. Zitteliana 94, 99–156.
Sitholey, R.V., 1940. Jurassic plants from Afghan-Turk-
istan. Memoirs of the Geological Survey of India, Palaeon-
tologia Indica, new series 4, 1–57.
Slater, S.M., Wellman, C.H., Romano, M., & Vajda, V.,
2018. Dinosaur plant interactions within a Middle
Jurassic ecosystem: palynology of the Burniston
Bay dinosaur footprint locality, Yorkshire, UK. [In:]
S.M. Slater, E. Kustatscher & V. Vajda (Eds): Jurassic
biodiversity and terrestrial environments. Palaeobiodi-
versity and Palaeoenvironments 98, 139–151.
Stampi, G. & Borel, G.D., 2002. A plate tectonic model
for the Paleozoic and Mesozoic constrained by dy-
namic plate boundaries and restored synthetic oce-
anic isochrons. Earth and Planetary Science Letters 196,
17–33.
Stewart, W.N. & Rothwell, G.W., 1993. Paleobotany and the
evolution of plants. Cambridge University Press, Cam-
bridge, 521 pp.
Stöcklin, J., 1974. Possible ancient continental margins in
Iran. [In:] Burke, C.A. & Drake, C.L. (Eds): The Geol-
ogy of Continental Margins, New York, Springer, pp.
873–887.
Stöcklin, J. & Setudehnia, A., 1971. Stratigraphic lexicon of
Iran, Part I: central, north and east Iran, 315, Report No.
18. Geological Survey of Iran, 338 pp.
Stöcklin, J. & Nabavi, M.H., 1971. Explanatory text of the
Boshruyeh Quadrangle map 1:250,000. Geological Quad-
rangle J7, 1–50.
Stukins, S., Jolley, D.W., McIlroy, D. & Hartley, A.J., 2013.
Middle Jurassic vegetation dynamics from allochtho-
nous palynological assemblages: an example from
a marginal marine depositional setting; Lajas Forma-
tion, Neuquén Basin, Argentina. Palaeogeography, Pal-
aeoclimatology, Palaeoecology 392, 117–127.
Sun, G., Miao, Y., Mosbrugger, V., & Ashraf, A.R., 2010.
The Upper Triassic to Middle Jurassic strata and o-
ras of the Junggar Basin, Xinjiang, Northwest China.
Palaeobiodiversity and Palaeoenvironments 90, 203–214,
https://doi.org/10.1007/s12549-010-0039-8
Takin, M., 1972. Iranian geology and continental drift in
the Middle East. Nature 235(5334), 147–150.
Tipper, G.H., 1921. The geology and mineral resources of
eastern Persia. Records of the Geological Survey of India
53, 51–80.
Tralau, H., 1967. Some Middle Jurassic microspores of
Southern Sweden. Geologiska föreningen 89, 469–472.
Traverse, A., 2007. Paleopalynology, Second edition, Dordre-
cht, Netherlands, 813 pp.
44 Saeed Maleki
Vaez-Javadi, F., 2018. Middle Jurassic ora from the Ho-
jedk Formation of Tabas, central East Iran: Biostratig-
raphy and palaeoclimate implications. Rivista Italiana
diPaleontologiaeStratigraa 124, 299–316.
Vaez-Javadi, F., 2019. Middle Jurassic palynology of the
southwest Tabas Block, Central-East Iran. Palynology
44, 551–562, doi:10.1080/01916122.2019.1637954
Vaez-Javadi, F., & Mirzaei-Ataabadi, M., 2006. Jurassic
plant macrofossils from the Hojedk Formation, Ker-
man area, east-Central Iran. Alcheringa 30, 63–96.
Vakhrameev, V.A., 1991. JurassicandCretaceousorasand
climates of the Earth. Cambridge University Press, 340
pp.
Vakhrameev, V.A., Dobruskina, I.A., Zalkinskaya, Y.D. &
Meyen, S.V., 1970. Paleozoic and Mesozoic oras of
Eurasia and the phytogeography of that time. Akade-
mie Nauka SSSR Institute Trudy 208, 1–424 (in Russian).
Van Konijnenburg-van Cittert, J.H.A., 2002. Ecology of
some Late Triassic to early Cretaceous ferns in Eura-
sia. Review of Palaeobotany and Palynology 119, 113–124.
Van Konijnenburg-van Cittert, J.H.A. & Van der Burgh,
J., 1989. The ora from the Kimmeridgian (Upper Ju-
rassic) of Culgower, Sutherland, Scotland. Review of
Palaeobotany and Palynology 61, 1–51.
Vickers, M.L., Hougard, I.W., Alsen, P., Ullmann, C.V.,
Jelby, M.E., Bedington, M. & Korte, C., 2022. Middle to
Late Jurassic palaeoclimatic and palaeoceanographic
trends in the Euro-Boreal region: Geochemical in-
sights from East Greenland belemnites. Palaeogeogra-
phy, Palaeoclimatology, Palaeoecology 597, 111014.
Volkheimer, W., Rauhut, O.W.M., Quattrocchio, M.E. &
Martinez, M.A., 2008. Jurassic paleoclimates in Ar-
gentina, a review. Revista de la Asociación Geológica Ar-
gentina 63, 549–556.
Wang, Y., Mosbrugger, V., & Zhang, H., 2005. Early to
middle Jurassic vegetation and climatic events in the
Qaidam Basin, Northwest China. Palaeogeography, Pal-
aeoclimatology, Palaeoecology 224, 200–216.
Watson, J. & Sincock, C., 1992. Bennettitales of the English
Wealden. Monograph of the Palaeontological Society,
228 pp.
Wilmsen, M., Fürsich, F.T. & Taheri, J., 2009. The Shem-
shak Group (Lower–Middle Jurassic) of the Binalud
Mountains, NE Iran: stratigraphy, depositional envi-
ronments, and geodynamic implications. Geological
Society of London, Special Publications 312, 175–188.
Zhang, Q., Gong, E., Zhang, Y., & Guan, C., 2021. Pal-
ynoora and palaeoclimate of the late Early Jurassic
(Toarcian) in eastern Liaoning, China. Palaeobiodiver-
sity and Palaeoenvironments 102, 73–88, doi:10.1007/
s12549-021-00489-w
Manuscript submitted: 3 November 2023
Revision accepted: 3 April 2024
