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2018 ● 40 ● 11
geodiversitas
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211
GEODIVERSITAS • 2018 • 40 (11) © Publications scientiques du Muséum national d’Histoire naturelle, Paris. www.geodiversitas.com
Humberto ASTIBIA
Departamento de Estratigrafía y Paleontología, Facultad de Ciencia y Tecnología,
Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU),
apartado de correos 644, 48080 Bilbao (Basque Country)
humberto.astibia@ehu.eus
Didier MERLE
Jean-Michel PACAUD
CR2P (CNRS, MNHN, UPMC, Sorbonne Université),
Département Origines et Évolution, Muséum national d’Histoire naturelle,
case postale 38, 57 rue Cuvier, F-75231 Paris cedex 05 (France)
didier.merle@mnhn.fr
pacaud@mnhn.fr
Javier ELORZA
Departamento de Mineralogía y Petrología, Facultad de Ciencia y Tecnología,
Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU),
apartado de correos 644, 48080 Bilbao (Basque Country)
josejavier.elorza@ehu.eus
Aitor PAYROS
Departamento de Estratigrafía y Paleontología, Facultad de Ciencia y Tecnología,
Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU),
apartado de correos 644, 48080 Bilbao (Basque Country)
a.payros@ehu.eus
Submitted on 2 November 2017 | accepted on 1 February 2018 | published on 7 June 2018
Gastropods and bivalves from the Eocene marly formations
of the Pamplona Basin and surrounding areas
(Navarre, western Pyrenees)
KEY WORDS
Gastropods,
bivalves,
Paleogene,
shallow-marine
sediments,
Pyrenean area,
new combinations,
new species.
urn:lsid:zoobank.org:pub:EF27BD11-00CB-42A7-BCFE-9D0D6152E0F1
Astibia H., Merle D. Pacaud J.-M., Elorza J. & Payros A. 2018. — Gastropods and bivalves from the Eocene marly
formations of the Pamplona Basin and surrounding areas (Navarre, western Pyrenees). Geodiversitas 40 (11): 211-257.
https://doi.org/10.5252/geodiversitas2018v40a11. http://geodiversitas.com/40/11
ABSTRACT
Gastropods and bivalve associations from the middle and ?upper Eocene (Bartonian and ?Priabonian)
sedimentary succession of the Pamplona Basin are described. is succession was accumulated in the
western part of the South Pyrenean peripheral foreland basin and extends from deep marine turbiditic
(Ezkaba Sandstone Formation) to deltaic (Pamplona Marl, Ardanatz Sandstone and Ilundain Marl
formations) and marginal marine deposits (Gendulain Formation). Fossils are generally fragmentary
and many correspond to remains that have undergone taphonomic reworking. Significant effects of
diagenesis are also detected, with evidence of compression or deformation, dissolution, aragonite-
calcite neomorfism and cementation by celestite. Bioerosion traces and fossil encrusters are common.
Fossils of 37 taxa, 25 gastropods and 12 bivalves, have been identified confidently. e number of
species is probably considerably higher, as the study of some fossils, mainly the most small-sized
Références manquantes :
Morton 2018
Cossmann 1903
de Boury 1883
Herrmannsen 1846
Schmidt 1818
Children 1823
Brongniart 1823
212 GEODIVERSITAS • 2018 • 40 (11)
Astibia H. et al.
MOTS CLÉS
Gastéropodes,
bivalves,
Paléogène,
sédiments marins peu
profonds,
Pyrénées,
combinaisons nouvelles,
espèce nouvelle.
species, is pending. One new species, Athleta (Volutospina) delvallei Astibia, Merle & Pacaud, n. sp.
(Gastropoda, Volutidae), is described herein. Fossil assemblages are comparable to those from the Eo-
cene of the Basque Coast (North Pyrenean area) and Aragon and Catalonia (west-central and eastern
part of South Pyrenean area). Most of the mollusc taxa seem to be endemic to the Pyrenean area, but
several Tethyan and Northern elements have also been recorded. ese results enlarge the database
for a better understanding of the evolution of global marine biodiversity throughout the Eocene.
RÉSUMÉ
Gastéropodes et bivalves des formations marneuses de l’Éocène du Bassin de Pampelune et de ses environs
(Navarre, Pyrénées occidentales).
Les associations de gastéropodes et de bivalves de la succession sédimentaire de l’Éocène moyen et
?supérieur (Bartonien et ?Priabonien) du Bassin de Pampelune sont décrites. Cette succession s’est
accumulée dans la partie occidentale du bassin d’avant-pays périphérique sud-pyrénéen et comprend
des dépôts marins turbiditiques profonds (Formation des Grès d’Ezkaba) des dépôts deltaïques (forma-
tions des Marnes de Pampelune, des Grès d’Ardanatz et des Marnes d’Ilundain) et des dépôts marins
marginaux (Formation Gendulain). Les fossiles sont généralement fragmentaires et beaucoup d’entre
eux correspondent à des restes remaniés. Des effets significatifs de la diagénèse sont également détectés,
avec des signes de compression ou de déformation, de dissolution, de néomorphisme aragonite-calcite
et de cimentation par célestine. Les traces de bioérosion et les fossiles d’organismes incrustants sont
fréquents. Les restes fossiles de 37 espèces, dont 25 correspondant à des gastéropodes et 12 à des
bivalves, ont été identifiés. Ce nombre pourrait être considérablement plus élevé, grâce à l’étude de
très petites espèces (micro-mollusques) qui reste à faire. Une nouvelle espèce, Athleta (Volutospina)
delvallei Astibia, Merle & Pacaud, n. sp. (Gastropoda, Volutidae), est décrite ici. Les associations
fossiles sont comparables à celles de l’Éocène de la côte basque (Région nord-pyrénéenne), d’Aragon
et de la Catalogne (parties centre-ouest et est de la Région sud-pyrénéenne). La plupart des taxons de
mollusques semble être endémique à la Région pyrénéenne, mais plusieurs éléments téthysiens et du
Nord de l’Europe ont également été enregistrés. Ces résultats élargissent la base de données au vu d’une
meilleure compréhension de l’évolution de la biodiversité marine mondiale tout au long de l’Éocène.
INTRODUCTION
During the Eocene the West Tethyan region was a marine
biodiversity hotspot (Renema et al. 2008). In the North-
ern Atlantic area, the middle Eocene (particularly during
the Lutetian) marine fauna of the Paris Basin showed an
extraordinary biodiversity, particularly regarding the mol-
luscs, and can consequently be regarded as an extension of
the West Tethyan hotspot (Merle 2008; Merle et al. 2008;
Huyghe et al. 2012). In fact, Merle (2008, 2009) indicated
the presence of species of Tethyan origin in the Paris Basin,
which contributed to enrich the biodiversity of this region.
During the Priabonian the biodiversity decreased signifi-
cantly in both sides of the Atlantic Ocean (Hansen 1988;
Lozouet 1997; Huyghe et al. 2012).
During the Eocene, the Pyrenean area constituted a tran-
sitional zone between the Tethyan and Northern Atlantic
domains. However, the Pyrenean middle/late Eocene mollusc
faunas are still relatively poorly documented. In the North
Pyrenean area, the classic works by d’Archiac (1846, 1850),
Bouillé (1873, 1876), Boussac (1911) and Cossmann (1921)
on the molluscs from the “Nummulitic” of the Basque coast
and Aquitaine have hardly been updated. More recent stud-
ies on Eocene molluscs have been carried out in Aragon and
Catalonia (South Pyrenean area), such as those by Villalta
Comella (1956), De Renzi (1971, 1996), Abad (2001), Pis-
era & Busquets (2002), Dominici & Kowalke (2007, 2014)
and Tomašových et al. (2014), among others.
Regarding the western Pyrenees, the first palaeontologi-
cal data from the Pamplona Basin and surrounding areas
came from French geologist Carez (1881). He reported the
occurrence of extensive marl units, which he referred to as
“marls of Serpula spirulaea”, and mentioned the abundance
of a small bivalve, which he named Plicatula pamplonensis
(Dimya pamplonensis (Carez, 1881)
n. comb.
, Calzada &
Astibia 1996). Marquina (1908) worked on Eocene strata
in Navarre, presented the demarcation of the nummulitic
zones and cited the presence of fossil stems of “Pentacrinus”
and Plicatula pamplonensis in the marls of the Pamplona
Basin. Later, Ruiz de Gaona (1947), Mendizábal & Ruiz
de Gaona (1949), and Ruiz de Gaona & Colom (1950)
described the foraminiferal content of these marls, suggested
a Bartonian age, and mentioned the occurrence of rich
macrofossil associations in some localities around the city
of Pamplona. Local micropaleontological determinations
were provided later by Puigdefábregas (1975) and Alameda
et al. (1993). More recently, macropaleontological works on
the bivalve Dimya pamplonensis
n. comb.
(Calzada & Asti-
bia 1996), turtles and sirenians (Astibia et al. 1999, 2005,
2006), sponges and corals (Astibia et al. 2014), brachiopods
(Bitner et al. 2016), and trace fossils (Payros et al. 2000;
Astibia et al. 2007, 2017) have been published. In this paper
213
Gastropods and bivalves from the Pamplona Basin (Eocene)
GEODIVERSITAS • 2018 • 40 (11)
we present our first results on the gastropods and bivalves
represented in the fossil associations of the Pamplona basin
and neighbouring areas. Medium and large-sized species,
alongside some smaller species, are herein reported, whe-
reas the study of most small-sized species is pending. Most
of the molluscs seem to be endemic to the Pyrenean area,
although several species from the Tethyan (Italy and Alps)
and Northern (Paris Basin and Normandy) domains have
also been recorded (Astibia et al. 2016), thus confirming the
role of the Pyrenean area in connecting the two domains.
e results exposed herein will further contribute to enlarge
the database for a better understanding of faunal gradients
and the evolution of global marine biodiversity throughout
the Eocene.
Erize & Mendiorotz Fms
10 km
Etxauri
Noain
E
A
GG
A
G
Terrestrial Oligo-Miocene
Ilundain Marl Fm
Pamplona Marl Fm
Older than Eocene
Hecho Gr
Shelfal
Lmsts
Tiebas
Na
30°N
40°N
200 m
10 km
PAMPLONA MARL Fm
ILUNDAIN MARL Fm
Gendulain Fm
Pamplona
Badoztain
Egues
Ardanatz
Aranguren
Itzagaondoa valley
Monreal
Arraitza
G: Gendulain Fm
A: Ardanatz Sst Fm
E: Ezkaba Sst Fm
Itzagaondoa valley
Aranguren Ardanatz
Egues
Badoztain
Arraitza
NW-SE
ARDANATZ
Sst Fm
fig. 1. — Above, simplied geological map of the study area in the central part of Navarre (western Pyrenees). The studied paleontological localities are in italics
and framed. The Eocene western European paleogeography is shown in inset (Na, Navarre). Below, synthetic NW-SE cross section of the study area, showing
the overall stratigraphy, sedimentary architecture and (projected) location of the studied sites.
214 GEODIVERSITAS • 2018 • 40 (11)
Astibia H. et al.
LOCATION, MATERIAL AND METHODS
e study area is located in the central part of Navarre, in the
South-western Pyrenees (Fig. 1). During the Eocene, the South
Pyrenean zone was a NW-trending foreland basin, located
adjacent to the south of an uplifting orogen. For most of the
Eocene it constituted a narrow gulf entering from the Bay of
Biscay at approximately 35°N palaeolatitude. Eventually, sedi-
ments derived from the uplifting and denuding Pyrenees filled
the basin. By middle-late Eocene (Bartonian-Priabonian) times
fluviodeltaic sedimentary systems were widespread throughout
the foreland basin (Plaziat 1981; Pujalte et al. 2002; Barnolas
et al. 2004).
is evolution is well recorded in the central part of Navarre
by alternating marly and sandy lithostratigraphic units (Fig. 1).
e lower part of this succession is represented by the Bartonian
Ezkaba Sandstone Formation, a channel-levee turbidite system
fed directly from the uplifting orogen to the north (Payros et al.
1997). e overlying Pamplona Marl, Ardanatz Sandstone and
Ilundain Marl formations mainly represent prodelta, delta front
and restricted platform paleoenvironments, respectively (Asti-
bia et al. 2005, 2014). Finally, the Late Eocene (Priabonian)
Gendulain Formation is composed of coastal deposits (Puig-
defábregas 1975; Payros et al. 2000). e latter unit contains
the youngest deposits with marine influence in the region.
e abundant micropaleontological content of these deposits
is dominated by foraminifera, but ostracods are also com-
mon. Body macrofossils are locally abundant in the Ardanatz
Sandstone and Ilundain Marl formations. e macrofauna is
mainly represented by macroforaminifera, hexactinellid and
lithistid sponges, scleractinian corals, bryozoans, brachiopods,
tube-dwelling polychaetes, molluscs (gastropods, bivalves,
cephalopods and scaphopods), arthropods (crustaceans), echi-
noderms (crinoid stalk fragments, plates – ossicles – of aster-
oids, and spines and test fragments of echinoids), shark teeth,
turtle plates as well as sirenian vertebrae and ribs (Calzada &
Astibia 1996; Astibia et al. 1999, 2005, 2006, 2014, 2016;
Buffrénil et al. 2008; Bitner et al. 2016).
e mollusc fossils studied herein were collected from several
outcrops, few kilometers from the city of Pamplona, which
expose: 1) the upper part of the Pamplona Marl Formation
(mainly in the surroundings of Egues; EG1, AZ1, IZ1 sections);
2) the transition between the Pamplona Marl Formation and
the Ardanatz Sandstone Formation (near the town of Badoz-
tain; BD1 section); 3) the Ardanatz Sandstone Formation or,
more precisely, its transition into the overlying Ilundain Marl
Formation (Ardanatz-Eguesibar, Aranguren and other locali-
ties; TR1, ZB1, AD1-AD6, AG1 sections); 4) the lower part
of the Ilundain Marl Formation, approximately 100 m above
its base (near the town of Arraitza; ARR1 section); and 5) the
uppermost part of the Ilundain Marl Formation (three locali-
ties of the Itzagaondoa Valley; IV section) (Figs 1, 2). Precise
location of the outcrops is deliberately omitted with the aim
of protecting the fossil sites, in accordance with Natural and
0
10
20
30
40
50
60
70
80
AD1.3
AD1.2
AD1.1
AD1
0 m
10
20
30
40
50
AG1.1
AG1.2
AG1.3
AG1.4
AG1
?
0
10
AD3
AD3.1
0
10
20
AD2.2
AD2
AD2.1
?
?
?
?
?
?
277 m 347 m 1589 m
fig. 2. — Tentative correlation of some sections across the transition between the Ardanatz Sandstone and the Ilundain Marls in the Ardanatz-Aranguren area
(see Fig. 1 for location), showing the stratigraphic position of the studied fossiliferous levels (sandstone beds are not to scale; modied from Astibia et al. 2014).
215
Gastropods and bivalves from the Pamplona Basin (Eocene)
GEODIVERSITAS • 2018 • 40 (11)
D
H
G
F
E
AC
B
fig. 3. — Taphonomic features, bioerosion borings and encrusters on fossil molluscs from the Eocene (Bartonian-?Priabonian) marly formations of the Pamplona
Basin and surrounding areas (Navarre, western Pyrenees): A, eld image of reworked fragmentary specimens of the bivalve Chlamys Röding, 1798 in a sandstone
bed of the Ardanatz-Eguesibar AD3 section; B, evidence of taphonomic smoothing, fragmentation and dissolution in a sample from the Ardanatz-Eguesibar AD2
section; C, eld image showing fragmentation in a specimen of Spondylus cf. caldesensis Carez, 1881 in the Ardanatz-Eguesibar AD5 section; D, probably clionid
sponge borings (Entobia Bronn, 1838) on a specimen (AD.17) of Nihonia a. transversaria (Lamarck, 1804) n. comb. from the Ardanatz-Eguesibar AD sections (section
and level unknown); E, bryozoan borings (Pinaceocladichnus Mayoral, 1988) on a specimen (AD2.2.1) of Nihonia a. transversaria (Lamarck, 1804) n. comb. from the
Ardanatz-Eguesibar AD2 section; F, boring, probably made by predatory gastropods (Oichnus Bromley, 1981), on a shell (IV.14) of Chama pellati Boussac, 1911 from
the Itzagaondoa Valley IV section; G, Borings, probably made by polychaetes (?Caulostrepsis Clarke, 1908), and encrusting bryozoans, polychaetes and bivalves on a
valve (AD.18) of Spondylus cisalpinus Brongniart, 1823 (ecomorph bifrons) from the Ardanatz-Eguesibar AD section (precise section and level unknown); H, Encrusting
bryozoans on a specimen of Athleta (Volutospina) delvallei Astibia, Merle & Pacaud, n. sp. (AD2.1.5) from the Ardanatz-Eguesibar AD2 section. Scale bars: 10 mm.
216 GEODIVERSITAS • 2018 • 40 (11)
Astibia H. et al.
Cultural Heritage legislation. However, further details can be
obtained from the corresponding author.
All fossils were cleaned with potassium hydroxide (90%,
flakes QP) and photographed after being covered with ammo-
nium chlorure. A selection of 17 thin sections of fossil gas-
tropods and bivalves was prepared for standard transmitted
light petrography, cathodoluminiscence (CL) and carbonate
staining with alizarin red S and potassium ferricyanide (fol-
lowing Dickson 1965). e mineralogy of 5 samples was
analyzed by X-ray diffraction (XRD).
e classification and nomenclator of Gastropoda fami-
lies of Bouchet & Rocroi et al. (2005) has been followed for
taxonomy. e classification of Carter et al. (2011) and the
glossary of Carter et al. (2012) were used for the Bivalvia. e
taxonomy of the studied specimens is detailed below in the
Systematic Palaeontology section. All fossils are provisionally
deposited in the Department of Stratigraphy and Palaeontol-
ogy of the University of the Basque Country (Universidad
del País Vasco/Euskal Herriko Unibertsitatea, UPV/EHU).
AbbreviAtions
Institutions
UPV/EHU Universidad del País Vasco/Euskal Herriko Unibert-
sitatea;
MNHN.F Muséum national d’Histoire naturelle, Collection de
Paléontologie, Paris.
Gastropods
H heigth;
W width.
Bivalves
H heigth, umbo-pallial diameter;
L length, antero-posterior diameter;
W thickness;
min minimum value;
mean value;
max maximum value;
n number of measured specimens.
All measurements are in millimeters. Numbers in parentheses
indicate approximate measures, due to the fragmentary nature
of many of fossils.
TAPHONOMY
biostrAtinomic And reworking processes
e Bartonian succession of the study area is very rich in micro-
fossils, but generally lacks macrofossils, only locally abundant.
Macrofossils associated with siliciclastics, i.e., sandstone beds
and silty and sandy marls, generally have poor preservation and
correspond to remains that underwent taphonomic reworking
(resedimentation and/or reelaboration, sensu Fernández López
2000). Such is the case of many disjointed and fragmentary
specimens of the bivalve Chlamys found in sandstone beds
(Fig. 3A), as well as of Cerithioidea and other gastropods in
sandy marls from Ardanatz-Eguesibar and Aranguren (Ardanatz
Sandstone), which commonly lost their protoconch, aperture
and early whorls, or are broken (disarticulation, smoothing
and fragmentation processes) (Fig. 3B).
Fossils included in marls, such as the silty marls of the
Ardanatz Sandstone and Ilundain Marl formations, despite
generally being fractured (fossil diagenetic fragmentation),
frequently correspond to entire specimens and hardly show
signs of abrasion. Examples include sponges and erected bryo-
zoans (Astibia et al. 2014), along with probably reclined, semi-
infaunal bivalves, such as Spondylus and Pycnodonte (Fig. 3C).
We can assume that they corresponded to demic organisms
whose remains suffered little, if any, taphonomic reworking.
In addition, many fossil shells show signs of bioerosion,
especially borings of sponges (Entobia isp.), bryozoans (Pina-
ceocladichnus isp.) and polychaetes (Caulostrepsis?) (Fig. 3D,
E, G) and holes (praedichnia of gastropods, Oichnus isp.)
(Figs 3F; 13N). Sessile encrusters (mainly bryozoans and
polychaetes) epizoozoans (sensu Taylor & Wilson 2003), both
in living and in dead hosts, are common (Figs 3G, H; 11C).
microstructure And fossil-diAgenetic processes
Fossil-diagenetic processes in gastropod and bivalves shells here
under study included compression or deformation, fragmen-
tation, dissolution (e.g. Figs 3A-C; 7; 8G), aragonite-calcite
neomorphism or, in some cases, cementation by celestite.
Fossil gastropods belonging to the species Ptychocerithium
baylei (Tournouër, 1874) n. comb. collected in the Ardanatz
Sandstone (AD1 section, levels AD1.3 and AD1.4; AG1 sec-
tion, level AG1.3, Figs 1; 2) were studied in thin section and
show the original structures affected by diagenesis.
e longitudinal sections of Ptychocerithium shells show evidence
of neomorphism processes with an intense development of large
crystals of equant calcite (ca). However, trace-ghost remains of
the original aragonitic crossed lamellar structure are still preserved
with a brown pseudo-pleochroism (Fig. 4A, B). A strong early
compression, which fragmented the shells into large pieces, with
a greater presence of the original aragonitic microstructure, is
also evident. Early cementation by large crystals of celestite (ce)
in the body cavity is dominant (Fig. 4C, D), filling all the empty
spaces, as shown by the absence of sediment. In detail, celestite
crystals display straight exfoliation planes, without bending, but
are broken as a consequence of their fragility (Fig. 4E, F). When
the gastropod body spaces were occupied by detrital sediment
and peloidal micrite, neomorphic processes also advanced into
the sediment, affecting the structure of the shell, with a strong
development of equant calcite crystals (Fig. 4G, H).
fig. 4. — Photomicrographs of thin-sections of Ptychocerithium baylei (Tournouër, 1874) n. comb. fossil shells from the transition between the Eocene (Bartonian-
?Priabonian) Ardanatz Sandstone and Ilundain Marl formations (Navarre, AD1 and AG1 sections), showing dierent structures aected by diagenesis: A, longitudinal
thin-section of specimen AG1.4.5 (parallel nicols), showing traces-ghosts of the original aragonitic crossed lamellar structure preserved as dark traces inside the
neoformed big crystals of equant calcite (ca). The shell cavity is lled with ne sediment (s) containing abundant terrigenous fragments, the distribution of which
adapts to the curvature of the shell; B, same as A with crossed nicols, showing a very thin generation of small crystals and neoformed big crystals of calcite in
the inner shell layer; C, specimen AD1.3.1 (parallel nicols), illustrating the area of shell compaction and breakage of the structure organized in dierent layers;
217
Gastropods and bivalves from the Pamplona Basin (Eocene)
GEODIVERSITAS • 2018 • 40 (11)
A
ca
ce
ce
ca
s
B
CD
EF
EF
1 mm 1 mm
1 mm 1 mm
independent fragments are supported by big celestite crystals (ce) with no deformation, which shows that celestite cementation was after compaction; D, same
as C with crossed nicols. Full cementation of the shell cavity by celestite crystals, no sediment being involved; E, specimen AD1.3.2 (parallel nicols), detail of the
shell cavity cemented by big celestite crystals (ce); shell fragments with a foliated structure are supported by celestite crystals; F, same as E with crossed nicols.
Celestite exfoliation (cleavage) planes present right angles, without bending, but are broken; G, general view of specimen AD1.4.1 (parallel nicols). Traces-ghosts
of the original aragonitic crossed lamellar structure are preserved as dark traces within neoformed, big equant calcite crystals (ca), showing pseudo-pleochroism
from colourless to brownish; H, same as G with crossed nicols. Scale bars: A-D, F-H: 1 mm; E, 0.5 mm.
218 GEODIVERSITAS • 2018 • 40 (11)
Astibia H. et al.
Celestite commonly forms as a result of rapid decomposition
of organic matter in a dysoxic microenvironment, which pro-
duces hydrogen sulfide. e latter can be oxidized to sulphate
by subsequent bacterial sulfoxidation. is sulphate produces
celestite when combined with mobile strontium, which is
released either from aragonite-to-calcite neomorphism (Taberner
et al. 2002) or from other processes, such as decomposition
of inherited sheet silicate minerals of continental origin with
a decrease-acidification of the pH (Baker & Bloomer 1988).
Diagenetic processes affecting fossil bivalves of the species
Spondylus cisalpinus Brongniart, 1823 (Ardanatz Sandstone,
AG1 section, level AG1.4; Ilundain Marl Formation, IV sec-
tion, Figs 1; 2), and Pycnodonte brongniarti (Bronn, 1831)
(Ilundain Marl Formation, IV section, Fig. 1) were also
studied in thin section.
Longitudinal sections of Spondylus observed with parallel
nicols show an inner shell layer characterized by a fibrous
prismatic structure (FP) with a great development of thin and
elongated prisms, initially composed of aragonite according
to Bøggild (1930: 269), slightly bent (Fig. 5A). e calcitic
crossed foliated structure (CF) is visible as the outer shell
layer, but it is less developed and lacks apparent continuity
with the FP structure. Spines protrude from the outer shell
layer in all Spondylus, consisting of pillars with crossed foli-
ated (CF) structure. e original structure of the middle layer,
belonging to the miostracum (?), was partially masked by the
FP structure. Finally, the CF structure is commonly covered
with a thin layer of micritic carbonate residues (cr) (Fig. 5A).
When observed under crossed nicols, evidence of diagenetic
alteration is clear, as the original aragonite prisms of the FP
structure are neomorphized and generate large calcite crystals
with different orientations (Fig. 5B).
In some samples, the middle shell layer (miostracum?), ini-
tially with aragonitic nacreous structure (n) and characterized
by its brown tones, has been well preserved, despite being
neomorphized during diagenesis (Fig. 5C). e FP structure
presents large calcite crystals and preserves small remnants
of modified thin prisms. However, the CF structure seems
to have been less sensitive to diagenetic alteration and shows
signs of non-transformation (Fig. 5D).
Under cathodoluminescence, both CF and FP structures
respond with dull luminescence, whereas micritic carbonate
residues (cr), show more intense red luminescence. e lack
of luminescent response of the CF and FP structures, despite
the evidence of intense neomorphism observed in FP, may
be indicative of early neomorphism in an oxidizing phreatic
environment, which did not permit incorporation of man-
ganese and iron cations to the calcite network (Fig. 5E-H).
Fossils of Pycnodonte brongniarti (Bronn, 1831) collected
from the Ilundain Marl Formation, when observed in thin
section, present a dominant complex crossed lamellar structure
(CL), with less developed vesicular (V) structure in transverse
sections (Fig. 6). In addition, repetitive thin and very long
cells (ec), initially empty, limited between thin layers of the
complex crossed lamellar structure (CL) have been observed
in the more bended areas (Fig. 6A). In these areas empty
cells (ec) are numerous and fractured, with evidence of small
wall movements which facilitated a full early cementation by
equant ferroan calcite crystals. Etching with Stained Aliza-
rin Red S and potassium ferricyanide permits distinction of
equant cement with mauve colour from the CL structure with
red colour (Fig. 6B) (Adams & MacKenzie 1998). In detail,
two stages of cementation can be determined, the first with
early development of small acicular crystals, characteristic
of meteoric and marine water mixing (a), and the second
cementation stage (b) with big equant ferroan calcite crystals.
e last cementation type (b), having ruled out its origin in
meteoric phreatic environments, is more characteristic of a
phreatic burial environment (Fig. 6C, D) (Tucker & Wright
1992; Tucker 1994). e CL structure is dominant and can
evolve to vesicular structure (V) in the bended areas, prob-
ably as adaptive strategy used by Pycnodonte brongniarti to
economize metabolic energy during growth of the shell.
At higher magnifications continuity seems to be continuity
between the lamellae of the CL structure to the V walls, with
the same optical behaviour in both the stained and equant
cements. Interestingly, the walls of the V microstructure
remain preserved, despite their thinness, as emphasized by
darker traces of micrite with organic remains, opaque ores
and fluid inclusions (Fig. 6E). Full cementation involves
large calcite crystals with a preferred orientation and exceeds
the limits of the vesicles. is strongly suggests a general
phreatic cementation (Fig. 6F) (Tucker & Wright 1992;
Tucker 1994). owever, diagenetic intensity was higher in
some samples, with partial destruction of the walls. It should
also be noted that when the transverse sections are bigger,
the formation of the structure (V) is visible through the
partitioning lines indicative of growth band separation and
disruption of the largest net vesicles, and then continues
with the growth of smaller vesicles. In addition, the fill-
fig. 5. — Photomicrographs of thin-sections of Spondylus cf. caldesensis Carez, 1881 and Spondylus cisalpinus Brongniart, 1823 (ecomorph bifrons) fossil shells
from the transition between the Eocene (Bartonian–?Priabonian) Ardanatz Sandstone and Ilundain Marl formations (Navarre, AD5 and AG1 sections), and of Spon-
dylus cisalpinus Brongniart, 1823 fossil shells from the uppermost part of the Ilundain Marl Formation (Navarre, IV section), showing dierent structures aected
by diagenesis: A, Specimen IV.15, longitudinal thin-section (parallel nicols) of Spondylus cisalpinus fossil shell showing an inner shell layer with brous prismatic
structure (FP) characterized by ne and long prisms. The original aragonite layer (according to Bøggild 1930: 269) was replaced by calcite. Above the inner shell
layer is the calcitic crossed foliated microstructure (CF), much less developed, which corresponds to the shell’s outer layer. The middle layer, corresponding to
the miostracum (?), has been obliterated by the FP structure. Micritic carbonate residues (cr) are observed along with the CF; B, same as A, with crossed nicols.
The strong neomorphism suered by the brous prismatic structure (FP) can be seen, with big calcite crystals showing dierent extinctions; however, the CF
structure is less aected by diagenesis; C, specimen AG1.4.1, longitudinal thin-section (parallel nicols) of Spondylus cisalpinus (ecomorph bifrons) with a strongly
modied brous prismatic structure (FP), originally aragonitic, where prisms are hardly preserved. The thin brownish area with aragonitic nacreous structure (n)
corresponds to the middle shell layer (miostracum?), which is covered with an outer shell layer with calcitic crossed foliated microstructure (CF); D, same as C
with crossed nicols. The neomorphic big calcite crystals extend to the thin brownish area of the middle shell layer (miostracum?). The crossed foliated structure
(CF) suered a lesser degree of neomorphism; E, specimen AG1.4.2, longitudinal thin-section (parallel nicols) of Spondylus cisalpinus (ecomorph bifrons). View
of the brous prismatic structure (FP), the crossed foliated microstructure (CF) and micritic carbonate residues (cr); F, same as E under cathodoluminescence.
219
Gastropods and bivalves from the Pamplona Basin (Eocene)
GEODIVERSITAS • 2018 • 40 (11)
A
CF
CF
CF
CF
CF
CF
FP
cr
cr
cr
cr
CF
CF
FP
FP
FP
n
FP
C
B
D
EF
GH
The dierent layers show dierent eects of fossil-diagenetic alteration. The red luminescence of the micritic carbonate residues (cr) indicates that they have
been more strongly aected by diagenesis than the shell layers, as the crossed foliated structure (CF) is non-luminescent and the prismatic structure (FP) is only
partially luminescent (dull luminiscence). The advance of diagenesis towards the shell interior is shown by the luminescent red colour extending along interpris-
matic paths; G, specimen AD5.1.1, thin-section (parallel nicols) of Spondylus cf. caldesensis. View of the crossed foliated structure (CF), with its spines/radial
ribs coated by micritic carbonate residues (cr); H, same as G under cathodoluminescence, showing non-luminescent crossed foliated structure (CF) along with
luminescent micritic carbonate residues (cr) and fractures aecting locally the CF structure. Scale bars: 1 mm.
220 GEODIVERSITAS • 2018 • 40 (11)
Astibia H. et al.
ing is produced by smaller crystals (polycrystalline in each
vesicle), involving a change in environmental conditions.
Regarding behaviour under cathodoluminescence, the CL
structure shows dull luminescence, indicating that this type
of structure was capable of enduring the diagenetic altera-
tion that undoubtedly affected all the shell. Conversely, the
acicular crystals, that were formed during the early infilling
of the empty cells (a), respond with weak luminescence, as
they were possibly generated in an oxidizing and mixing
aqueous environment. e subsequent filling with equant
calcite cement (b), much more luminescent in bright red,
suggests a reducing environment and incorporation of iron
and manganese into the calcite network (Fig. 6G). A similar
behaviour can be deduced to have occurred between the
CL structure and the walls of the V structure, which show
very low luminescence in comparison to the cement that
filled the vesicles, which produces generally intense red
colours (Fig. 6H).
In summary, significant effects of diagenesis were observed
in the fossils studied. In the gastropods, neomorphism
processes with formation of large crystals of equant calcite
occurred when the body cavity was filled with early detrital
sediment. In other specimens lacking intrashell sediment,
broken trace-ghosts of the original aragonitic crossed lamel-
lar structure are still preserved and early cementation by
precipitation of large celestite crystals within the body
cavity can be observed.
Different diagenetic behaviours can also be deduced for
Spondylus fossil shells depending on their structure. e CF
structure is more resistant than the FP structure, in which
original aragonite prisms are neomorphized and generate
large calcite crystals with different orientations. is obser-
vation is supported by cathodoluminescence.
Pycnodonte fossil structures are more complex and allow
the diagenetic evolution to be better established. e CL
and V structures are dominant and resistant to diagenesis.
e cements incorporated into empty cells and V structures
allow the identification of two diagenetic stages. e first
cement (a) was in all likelihood generated in an oxidizing
and mixing aqueous environment, whereas the second (b)
is considered as characteristic of a phreatic burial envi-
ronment. is observation agrees with stratigraphic and
micropaleontological data (see below: Fossil associations
and palaeoenvironments), which indicate that the fossilif-
erous strata of the uppermost Ilundain Marl Formation in
the Itzagaondoa valley, where fossils of Pycnodonte brongni-
arti are abundant, were deposited in a shallow inner shelf
environment.
SYSTEMATIC PALAEONTOLOGY
Phylum MOLLUSCA Linnaeus, 1758
Class GASTROPODA Cuvier, 1795
Clade (Superordenr) VETIGASTROPODA
Salvini-Plawen, 1980
Superfamily pleurotomArioideA Swainson, 1840
Family pleurotomAriidAe Swainson, 1840
Genus Leptomaria Eudes-Deslongchamps, 1864
t
ype
species
. — Pleurotomaria amonea Eudes-Deslongchamps,
1849 by original designation.
Leptomaria peresii (d’Orbigny, 1850)
(Fig. 7A-D)
Pleurotomaria peresii d’Orbigny, 1850: 313.
Pleurotomaria nicacensis Bayan, 1870: 12.
Conotomaria peresii – Benfrika 1994: 99.
Leptomaria peresii – Pacaud 2004: 620.
m
AteriAl
. — Ardanatz Sandstone. AD4 section: 2 incomplete and
somewhat laterally compressed specimens from level AD4.1 (ap-
prox. c. equivalent to AD3.1). 2 fragmentary specimens from AD
sections (section and level unknown). AG1 section: 2 fragments
from level AG1.2.
dimensions. — H = (>25.0)-42.0; W = (>32.0)-(>39.0).
description
High and thick trochiform (trochoid) shell; protoconch
pausispiral, homostrophic, smooth, preserved in one of the
specimens; base convex; umbilicus present, preserved in one
specimen (?); granular surface sculpture, with spiral cords and
wavy and weak axial ribs; ornamentation of the adapical part
of adult whorls above seleniarea more marked, with prosocline
(tri-) nodular axial ribs (spiral cords acquire granular appear-
ance); abapical part below seleniarea with thin spiral cords and
ortocline-opisthocline axial ribs. Aperture mixing, U-shaped
slit unpreserved, but seleniarea visible below shoulder (in the
apical part of the whorls), narrow, marked by scaly, regularly
spaced and opistocyrtic scars.
remArks
e high conispiral shell and the presence of seleniarea allow
assignation of these remains to the family Pleurotomariidae.
fig. 6. — Photomicrographs of thin-sections of Pycnodonte brongniarti (Bronn, 1831) fossil shells, from the uppermost part of the Eocene (Bartonian-?Priabonian)
Ilundain Marl Formation (Navarre, IV section), showing dierent structures aected by diagenesis: A, longitudinal thin-section of specimen IV.16 (crossed nicols),
showing the complex crossed lamellar structure (CL), along with the vesicular structure (V) and empty cells (ec) delimited by CL thin walls, later lled by spatic
cement with equant crystals; B, specimen IV.17 (crossed nicols), curvature area where the thin layers with crossed lamellar structure (CL) generate empty cells
(ec), later broken and lled with equant calcite cement. Staining with Alizarin Red S and potassium ferricyanide allows distinction of carbonate minerals contain-
ing Fe+2 (ferroan minerals) from those with little or no iron (non-ferroan minerals). The CL structure has an intense red colour (non-ferroan calcite) whereas the
calcite cement shows mauve colour (ferroan calcite); C, specimen IV.16 (crossed nicols), detail of (originally) empty cells, whose thin walls with crossed lamellar
structure (CL) were broken and slightly displaced. Two cementation stages are observed: a, early acicular growth only on one side of the wall fragments (typical
of the phreatic marine area); and b, later equant calcite cementation, inlling completely the original empty spaces; D, specimen IV.18 (crossed nicols), detail
of alternating crossed lamellar structure (CL), stained in red colour, and vesicular structure (V), generally displaying a lenticular arrangement; E, specimen IV.16
221
Gastropods and bivalves from the Pamplona Basin (Eocene)
GEODIVERSITAS • 2018 • 40 (11)
A
CL
CL
CL
CL
CL
a
b
ec
ec
CLV
V
V
V
V
CL
CL
a
b
B
CD
EF
GH
(parallel nicols), detail of the vesicular structure (V), where the thin walls show organic matter remains and evidence of iron ores; F, same as E, with crossed
nicols. The equant cementation involves big calcite crystals which are not deformed and cross the vesicle walls, typical evidence of cementation in phreatic en-
vironments; G, specimen IV.19 under cathodoluminescence. The thin layer with crossed lamellar structure (CL) hardly shows luminescence (non-luminescence),
while the equant calcite cement inlling the cells is composed of red luminescent big crystals. In detail, some cement crystals (a) associated with the walls are
non-luminescent and suggest oxidizing environments, whereas the subsequent lling of the central area, in red colour (b), shows evidence of a reducing environ-
ment; H, specimen IV.19, showing the complex crossed lamellar (CL) and vesicular (V) structures under cathodoluminescence. The CL structure and the vesicle
walls show weak (dull) luminescence, while the equant calcite cement inlling the vesicles shows intense red colour. Scale bars: A-D, G, H, 1 mm; E, F, 0.3 mm.
222 GEODIVERSITAS • 2018 • 40 (11)
Astibia H. et al.
e second feature excludes these from Trochoidea. e nar-
row seleniarea, its location in the apical part of the whorls and
the rather granular sculpture of the shell, are all indicatives of
the genus Leptomaria (see Pacaud 2004, 2007).
Leptomaria peresii (d’Orbigny, 1850) was defined in the
Priabonian of the Fontaine du Jarrier (Alpes-Maritimes)
(MNHN.F.R64076, d’Orbigny collection). It exhibits similar
proportions to those of the Danian species Leptomaria penul-
tima (d’Orbigny, 1850), but its spiral ornamentation is more
marked, with thicker and wider cords (see Pacaud 2004, 2007).
e occurrence of Pleurotomariidae has previously been
mentioned in Eocene strata of neighbouring geological regions.
Boussac (1911: pl. 4, fig. 6) figured and assigned a fossil
from the Eocene of La Gourèpe, in the Paleogene series of
the Basque Coast (southwestern Aquitaine Basin), in the
surroundings of the town of Biarritz/Miarritze, to “Pleuro-
tomaria” lamarcki Mayer, 1876. Farrés (1961) and Farrés &
Staid-Staadt (1964) cited, but did not illustrate, two species
as Pleurotomaria deshayesi Bellardi, 1852 (a junior subjective
synonym of L. peresii, see Pacaud 2007) and as Pleurotomaria
cf. concavata [sic] Deshayes, 1832 (a species attributed to the
genus Chelotia) in the Bartonian-Priabonian of Gurb (Vic
region, Catalonia).
Clade (Superorder) CAENOGASTROPODA Cox, 1960
Clade (Order) SORBEOCONCHA
Ponder & Lindberg, 1997
Superfamily CERITHIOIDEA Fleming, 1822
Family cerithiidAe Fleming, 1822
Genus Ptychocerithium Sacco, 1895
type species. — Cerithium granulinum Bonelli in Michelotti, 1840
by original designation.
Ptychocerithium baylei (Tournouër, 1874) n. comb.
(Fig. 7E-J)
Cerithium baylei Tournouër, 1874: 528.
Cerithium suessi Tournouër in Bouillé, 1873: 463, pl. 5, fig. 12 (non
Gemmellaro, 1868).
Cerithium johannae Tournouër in Bouillé, 1873: 20, 21, 37, pl. 5,
fig. 11.
Cerithium sp. – Tournouër in Bouillé 1876: 250.
Ptychocerithium johannae – Boussac 1911: 34, pl. 7, fig. 16. — Asti-
bia et al. 2016: 13, fig. 6a.
m
AteriAl
. — Ardanatz Sandstone. AD1 and AD2 sections: 1 speci-
men from level AD1.2; 2 specimens from level AD1.3; 13 specimen
from level AD2.1; 1 specimens from level AD2.2. AG1 section:
12 specimens from level AG1.3; 1 specimen from level AG1.4. Ilun-
dain Marl Formation, IV section: 13 specimens. All are fragmentary
specimens, lacking the apical part and the aperture (or most of it).
d
imensions
. — Largest specimen: H > 34.0; W = 13.0 (incomplete
specimen, about 42.0 high complete?).
description
Shell medium-sized; cerithiform; multi-whorled (about 12
whorls in adult specimens); protoconch not preserved; tel-
eoconch long, turriculate, abapical half straight or slightly
convex; apical angle about (17)-22 degrees; spire whorls flat
sided; spiral sculpture consists of three well developed primary
or major beaded, granulated, cords (spiral ribs P1, P2, P3),
four beaded secondary cords (adapically to P1, between P1
and P2 and P3, abapically to P3), tertiary cords occurring
between other cords; P1 more developed than the others in
the last two whorls of the spire and in the body whorl. Mor-
phological variability occurs, with specimens with the second
secondary beaded cord almost as developed as the two first
primary cords (P1 and P2), but others (IV section) with P3
very poorly developed (Fig. 7I); growth lines opistocirtes-
ortoclines; primary beads or nodules situated at the intersec-
tion (cross-over points) with generally not very prominent
axial ribs; the number of primary beads of the last five whorls
of the spire ranges from 14 or 13, 16 more frequently, to
18; body or last whorl with three major beaded cords, beads
considerably more elongated, no less than eight cords (four
“primary” and four “secondary” intercalated) below the three
major granulated ones, strong varix opposite aperture (abap-
ertural side); aperture always broken, relatively small, about
16-20% percent of the total shell length (?), with remains of
well developed (?) inner lip, posterior (anal) canal and mod-
erately extended (?) anterior siphonal canal.
remArks
is species is the most abundant gastropod in the fossil associa-
tions of the Ardanatz Sandstone. e presence of Cerithiidae
(Cerithium sp.) in the Bartonian of Ardanatz-Eguesibar was
alredy mentioned by Ruiz de Gaona (1947), Mendizábal &
Ruiz de Gaona (1949) and Ruiz de Gaona & Colom (1950).
e studied specimens are similar to those first described
as “Cerithium sp. indét.” by Tournouër (1864) and later as
“Cerithium suessi” (Tournouër in Bouillé 1873: 463, pl. 5,
fig. 12) in the marls with Serpula spirulaea (Rotularia spiru-
laea (Lamarck, 1818)) in the north of Peyrehorade (Landes,
Aquitaine Basin). Later Tournouër (1874) renamed C. suessi
(correction for primary homonymy, pro Cerithium suessi
Tournouër, 1873 non Gemmellaro, 1868) as Cerithium baylei.
Our specimens are comparable to the syntypes of Cerithium
baylei from the Priabonian of Peyrehorade in the Tournouër
collection (MNHN.F.B21040).
A species closely related to Ptychocerithium baylei n. comb. is
P. johannae (Tournouër in Bouillé, 1873), from the Paleogene
series of the Basque Coast, outcrop of Villa Lady Bruce, in
the surroundings of Biarritz/Miarritze (Bartonian-Priabonian,
Côte des Basques Marls Formation, southwestern Aquitaine
Basin, Jacquot 1864; Mathelin & Sztràkos 1993; Sztràkos
et al. 1998, 2010). Described as “Cerithium johannae” by
Tournouër (in Bouillé 1873: 446, pl. 5, fig. 11), this species
was also described by Boussac (1911: pl.7, fig.16) from the
outcrop of Villa Marbella, the same as Lady Bruce according
to this author. However, P. baylei n. comb. and P. johannae
present a somewhat different morphology. In P. baylei n.
223
Gastropods and bivalves from the Pamplona Basin (Eocene)
GEODIVERSITAS • 2018 • 40 (11)
AB C
D
O
N
L
M
K
J
I
H
GFE
Q
PR
fig. 7. — Fossils of gastropods from the Eocene (Bartonian-?Priabonian) marly formations of the Pamplona Basin and surrounding areas (Navarre, western Pyr-
enees): A-D, Pleurotomaridae indet.: A, B, AD4.1.1, apertural and oblique apical views; C, AD.19, lateral view; D, AG1.2.1, oblique apical view; E-J, Ptycho cerithium
baylei (Tournouër, 1874) n. comb.: E, AG1.4.3, apertural view; F, AG1.3.1, apertural view; G, AD2.1.6, apertural view; H, AG1.3.2; I, IV.20; J, IV.14; K-O, Diastoma
costellatum (Lamarck, 1804): K, IV.22, dorsal view; L, AD1.3.3, apertural view; M, IV.24; N, IV.23, apertural view; O, IV.25, apertural view? P, Q, Benoistia sp.: IV.33,
dorsal and ventral views; R, Jponsia sp., IV.1, dorsal view. Scale bars: 5 mm.
224 GEODIVERSITAS • 2018 • 40 (11)
Astibia H. et al.
comb. the primary spiral sculpture consists of well developed
beaded or granulated cords. On the contrary, in P. johannae,
as pointed out by Tournouër (see Bouillé 1873: 446), the
granulations are only well developed in the first teleoconchal
whorls, being significantly attenuated in the next whorls and
resulting in smoother spiral cords.
e morphology of our specimens coincides with that of
two specimens of P. johannae included in the Cossmann col-
lection from the Bartonian of Biarritz (MNHN.F.J12641).
However, due to the presence of well-developed beaded or
granulated cords, in our opinion these two specimens should
be better assigned to P. baylei n. comb.
e morphology is also quite similar to that described by
Tournouër for “Cerithium biarritzense” (in Bouillé 1876: 62,
pl. 3, fig. 5), another of the “Cérites des couches à Serpula
spirulaea” (in denomination of Boussac 1911) from the site
of Lady Bruce. It is very likely that P. baylei n. comb. and
C. biarritzense are synonymous.
P. baylei n. comb. differs from P. sublamellosum (d’Archiac,
1846) by having flat and not slightly convex spire whorl
profiles (see d’Archiac 1846: pl. 9, fig. 8). Furthermore,
one specimen of P. sublamellosum illustrated – as Cerithium
sublamellosum – by Boussac (1911: 11, fig. 11) and another
four fossils assigned to the same species in the Cossmann
collection (MNHN.F.J12761) from Biarritz, exhibit four
spiral cords, and not three as in P. baylei n. comb., with less
developed beads but more marked axial ribs than in P. baylei
n. comb. Ptychocerithium gentili (Boussac, 1911), also present
in the Bartonian of Biarritz (Villa Marbella site), has four
spiral cords (see Boussac 1911: 22, fig. 5).
Gastropods are abundant in the Eocene of Catalonia, in
the eastern part of the South Pyrenean area (Carez 1881;
Cossmann 1898a, 1906; Farrés 1961; Farrés & Staid-Staadt
1964; De Renzi 1971; Dominici & Kowalke 2014). Coss-
mann (1898a, 1906) discusses and defines many gastropod
species from the Eocene of Catalonia, but P. baylei n. comb.
was not cited.
Family diAstomAtidAe Cossmann, 1894
Genus Diastoma Deshayes, 1861
type species. — Melania costellata Lamarck, 1804 by monotypy.
Diastoma costellatum (Lamarck, 1804)
(Fig. 7K-O)
Diastoma costellatum Lamarck, 1804b: 430.
Diastoma hispanicum Cossmann, 1906: 442, pl. C, figs 15-17.
Diastoma biarritzense Oppenheim, 1906: 82, 83, pl. 9, fig. 18. —
Boussac 1911: 48, pl. 11, fig. 10.
m
AteriAl
. — Ardanatz Sandstone. 3 specimens from AD sec-
tions (levels unknown). AD1 and AD2 sections: 1 specimen from
level AD1.3; 1 specimen from level AD2.1; 1 specimen from level
AD2.2. AG1 section: 3 fragments from level AG1.4. Ilundain Marl
Formation, IV section: 37 specimens. All incomplete specimens,
aperture not preserved.
dimensions. — Largest specimen: H > 25.0; W = 8.5 (incomplete
specimen, about 30.0 high complete?).
descripton
Shell medium-sized; slender, turriculate; whorls convex-sided,
incised sutures; main ornamentation consist of 13-19 regularly
spaced axial ribs, with one or two varices on each whorl, in
general not very strong, crossed by 4-5 equally spaced pri-
mary cords (spiral ribs) in early whorls, 7-10 in adult spire,
14 or more in the last whorl; intercalated secondary and even
some tertiary spiral ribs; variability in the development of the
axial sculpture is observed, especially in the varices, from very
marked to virtually absent; in some specimens adapical third
spirals and axial ribs are coarse, thicker, with granulose and
elongated intersections.
remArks
is species is the most abundant gastropod in the fossil
associations from the outcrops of the Itzagaondoa Valley (IV
section), in the uppermost part of the Ilundain Marl Forma-
tion. e morphology of the shells is quite similar to Diastoma
costellatum (Lamarck, 1804), a species defined in the Lutetian
strata of the Paris Basin. However, the ornamentation of our
fossils is more marked than in the specimens of D. costellatum
from the Lutetian strata of Damery (Marne) (see in Cour-
ville et al. 2012), Chaussy (Val-d’Oise, MNHN.F.J02476,
MNHN.F.J12812, Cossmann coll.) or Grignon (Yvelines,
MNHN.F.J03710, Cossmann coll.) of the Paris Basin, and
markedly more pronounced than in the holotype of Diastoma
imbricatum Cossmann, 1898 from the Bartonian of Bois-
Gouët (Loire-Atlantique, MNHN.F.J04722, Cossmann coll.)
(Cossmann 1898b). In this sense, it bears greater resemblance
with the species Diastoma hispanicum Cossmann, 1906 from
the Early Eocene of Perauba (Catalonia), but in our opinion
the differences between D. costellatum and D. hispanicum
are not significant. Farrés & Staid-Staadt (1964) cite the
occurrence of D. costellatum in the “Biarritzian” (Bartonian-
Priabonian, Cascella & Dinarès-Turell 2009; Costa et al.
2013) from the Comarca de Vic (Catalonia). D. Diastoma
costellatum is also mentioned and figured by Boussac (1911:
pl. 8, fig. 7; pl. 11, fig. 9) in the “Nummulitique” of Biarritz,
from the Auversian (Bartonian) of Villa Marbella and from
the Bartonian or early Priabonian of the Côte des Basques
Marls Formation (southwestern Aquitaine Basin). e Coss-
mann collection includes three specimens of D. costellatum
(MNHN.F.J12818) and three specimens of Diastoma costel-
latum elongatum (Brongniart, 1823) (MNHN.F.J12822) from
Biarritz, and they are fully comparable to those of Navarre.
Oppenheim (1906: 82, pl. 9, fig. 18) described a new spe-
cies, Diastoma biarritzense, from the marls of the Côte des
Basques. Boussac (1911: pl. 11, fig. 10) described a shell
fragment from the Côte des Basques, which he also assigned
to the species Diastoma biarritzense Oppenheim, 1906, due
to its lower number and less development axial ribs – similar
225
Gastropods and bivalves from the Pamplona Basin (Eocene)
GEODIVERSITAS • 2018 • 40 (11)
to the specimen AD1.3.3 from Ardanatz sandstone (Boussac
1911: Pl.pl. 5, Fig.fig. 12). However, in our opinion the mor-
phological features of D. biarritzense fit within the variability
of D. costellatum. Puigdefábregas (1975, determinations by
Villalta Comella) mentioned the presence of D. costellatum
elongatum and D. costellatum biarritzense in the Eocene marls
of Binacua and San Román de Basa (Pamplona Marls sensu
lato, Jaca Basin, west-central part of the South Pyrenean area),
which are all situated in the neighbouring territory of Huesca
(Aragon), about 120 km to the southeast of our study area.
Family brAchytremAtidAe Cossmann, 1906
Genus Benoistia Cossmann, 1900
t
ype
species
. — Cerithium muricoides Lamarck, 1804 par monotypy.
Benoistia sp.
(Fig. 7P, Q)
mAteriAl. — Ilundain Marl Formation, IV section: 1 incomplete
specimen.
d
imensions
. — H > 18.0; W = (12.0) (incomplete specimen, about
22 mm high complete).
description
Shell medium sized. Four last whorls preserved. Conical and
slightly elongated teleoconch. Suture moderately deep. Axial
sculpture of 5-8 low ribs becoming less and less marked dur-
ing the growth. On the spire, one strong primary cord on the
sutural ramp and two other primary cords on the convex part
of the whorl. On the last whorl, one strong primary cord on
the sutural ramp and around four other primary cords on the
convex part of the whorl. On the two last whorls, appearance
of secondary cords and threads. Numerous granules on the
primary cords and major secondary cords. Aperture not visible.
remArks
e elongated shape of Benoistia vidali Cossmann, 1906
from the Early Eocene of Catalonia (Perauba) strongly
resembles Benoistia sp. However, since the early teleoconch
whorls, the axial ribs are well defined and strongly nodu-
lose, whereas Benoistia sp. bear only small nodules. On the
last whorl, Benoistia vidali displays subspinose nodules on
the shoulder, whereas they are developed in Benoistia sp.
Benoistia bofilli Cossmann, 1906, from the Early Eocene
of Catalonia (Perauba), differs by a shorter shape, more
marked axial ribs and a less granulose surface. B. Benoistia
muricoides (Lamarck, 1804), from the Middle Eocene of
the Paris Basin, differs by a shorter shape and by nodulose
and subpinose ribs, but it shares a granulose surface with
Benoista sp. B. acutidens (Deshayes, 1833) from the Lute-
tian of the Paris Basin shares an elevated spire, but is eas-
ily distinguishing by its sculpture in which the first spiral
cord of the convex part of the whorl forms a strong keel.
In addition, the surface of the shell is not granulose. e
Rupelian species B. boblayi (Deshayes, 1833) posseses a
more conical shell and its axial ribs are almost not marked.
Finally this species of Benoistia seems to be new, but more
material is needed to complete its shell description and
particularly the aperture.
Family pAchychilidAe Fischer & Crosse, 1892
Genus Jponsia Pacaud & Harzhauser, 2012
type species. — Melania cuvieri Deshayes, 1825 by original des-
ignation.
Jponsia sp.
(Figs 7R; 8A, B)
m
AteriAl
. — Ilundain Marl Formation, four fragmentary speci-
mens from IV section.
dimensions. — Largest specimen: H > 50.0; W = (22.0) (incom-
plete specimen, about 70 mm high complete?).
description
Shell medium-large sized; cerithiform, robust, long spire; strong
axial sculpture with coarse ribs (varices), slightly spiny and
opisthocline, especially developed in the middle and abapical
parts, about 11 (preserved young spire)-9(10) (adult spire)
per whorl; adapical third of whorls depressed and rather flat,
forming a fringe or band with thin axial ribs (growth lines?)
and two separate upper and lower grooves (furrows) in the
larger specimens. Spiral sculpture marked by furrows giving
the axial ribs an imbricated-staggered outline. Last whorl
small, less than a third of the total height of the shell, with
net spiral ornamentation down to the base.
remArks
In a recent work Pacaud & Harzhauser (2012) reviewed the
Pachychilidae of the European Paleogene, suggesting the
creation of three new genera: Jponsia, Moniquia and Eginea.
ese authors included in the new genera some Cretaceous
and Paleogene species, previously assigned to genera such
as Faunus De Montfort, 1810, Melanatria Bowdich, 1822,
Pirena Lamarck, 1822 or Tinnyea Hantken, 1887.
Although the material available in this study is very limited,
in principle, the genus Jponsia seem to be more appropriate
than Moniquia, because the development of the spiral sculp-
ture is greater; unlike the development of the spiny sculpture,
which is smaller and adapically not abaxially oriented.
e morphology of our specimens is quite similar to that
of the fossils which Villalta Comella (1956: 152-154, pl. 4,
fig. 1) assigned to Faunus (Melanatria) undosus (Brongniart,
1823), from the Bartonian marls of San Román de Basa
(Huesca, Jaca Basin, South Pyrenean area). It is also com-
parable to a specimen of Jponsia undosa (Brongniart, 1823)
figured by Pacaud & Harzhauser (2012: pl. 2, fig. 4) from
the Bartonian of Roncà (Italy), although the fragmentary
226 GEODIVERSITAS • 2018 • 40 (11)
Astibia H. et al.
state of both the Italian and our specimens does not allow
further insight.
Family turritellidAe Lovén, 1847
Genus Haustator Montfort, 1810
type species. — Haustator gallicus Montfort, 1810 by monotypy.
Haustator altavillensis (Cossmann & Pissarro, 1900)
(Fig. 8C-G)
Turritella altavillensis Cossmann & Pissarro, 1900: 196, pl. 20, figs 6-7.
Turritella (Haustator) altavillensis – Villalta Comella 1956: 143,
144, pl. 3, figs 1a-1e.
mAteriAl. — Ardanatz Sandstone. 4 specimens from AD sections
(levels unknown). AD1 and AD2 sections: 1 specimen from level
AD1.2; 1 specimen from level AD2.1; 2 specimens from level
AD2.2. Ilundain Marl Formation, IV section: 4 fragments. All
incomplete specimens, protoconch, early teleoconchal whorls and
aperture not preserved.
d
imensions
. — Largest specimen: H > 47.0; W = 15.0 (incomplete
specimen, about 80 mm high complete?).
description
Shell large-sized, turriculate, sharply conical; protoconch and
aperture are missing in all specimens; apical angle about 10-11
degrees (?); adult whorls flat-sided, basally carinate, sculptured
with 7-8 fine spiral keeled cords, sharps, more tightly packed
the first three or four cords, more separate and developed the
following, being the 7th (the penultimate cord, spiral C? of
Marwick 1957) the most prominent; the last two cords may
form a basal carination, variable in development, and some-
times seem to protrude slightly above the next whorl; space
between cords (spiral grooves) concave; adult growth lines
between the sutures (outer lip trace) opistocirtes-prosoclines,
with moderately oblique lateral sinus; growth lines develop
a fine axial costulation, pointed by partial dissolution of the
fossil shells. e intersection between the thin axial ornamen-
tation and the spiral cords gives them a finely and irregularly
toothed, granulated appearance.
remArks
e presence of Turritellidae among the gastropods from the
Eocene of marly formations of Navarre was already mentioned
by Ruiz de Gaona (1947), Mendizábal & Ruiz de Gaona (1949)
and Ruiz de Gaona & Colom (1950), who cited the species
“Turritella duvali” in the Bartonian of Ardanatz-Eguesibar.
e genus Turritella Lamarck, 1799 is widely used for
many turritelline species. Turritelline genus-level systemat-
ics remains unclear (Allmon 1996). According to Marwick
(1957) and Tracey & Todd (1996), the flat-sided adult whorls
and prominent primary spirals C forming a basal carination
allow the studied fossils to be tentatively assigned to Haustator,
but unfortunately the protoconch and the early teleoconch,
which are important to reliably identify this genus, are miss-
ing in our material.
During the past, several species of the genus Turritella have
been described in the Paleogene series of Bearn and the Basque
Coast (southwestern Aquitaine Basin) and Catalonia (eastern
margin of the Ebro Basin). D’Archiac (1850: pl. 13, fig. 19)
described and figured a fossil of Turritella inscripta d’Archiac,
1850 (=synonym of ?Haustator inscripta (d’Archiac, 1850)),
a species established from perhaps too fragmentary speci-
mens. ree specimens of ?H. inscripta from the Eocene of
Biarritz (Villa Marbella, Côte des Basques Marls Formation;
MNHN.F.J12239, Cossmann coll.) present, as diagnosed by
d’Archiac (1850), two carina on every whorl, a morphology
distinctively different to that in our fossils. D’Archiac (1850)
also cited Turritella carinifera Deshayes, 1832 (=synonym of
Haustator contractus (Sowerby J. de C. in Dixon, 1850)) in
the Eocene of Biarritz and Pau (Bosdarros/Lo Bòsc d’Arròs).
Rouault (1850: pl. 15, figs. 13, 14) described and figured two
specimens of T. carinifera from the Early Eocene of Bosdarros
(=synonym of Haustator pseudoelegans (Cossmann, 1923)).
Bouillé (1876) also cited T. carinifera from the sites of Lady
Bruce and Phare (Roche d’Haïtzar) near Biarritz. Our speci-
mens exhibit flat sides and basal carina, but they are more
elongate than those figured by Rouault (1850). ey are in
fact more alike a specimen of T. carinifera, figured by Coss-
mann & Pissarro (1910: pl. 20, fig. 125-4) from the Lutetian
of Chaumont-en-Vexin (Paris Basin), although spiral cords
of the latter seem to be more numerous and more regularly
distributed on every whorl than in fossils from Navarre. On
the other hand, Newton (1912) suggested T. oppenheimi as
a replacement name for T. carinifera Deshayes, 1832 (non
Lamarck, 1822, a recent species) (Tracey & Todd 1996), but
T. oppenheimi is a subjective synonym of Haustator contractus
(Sowerby J. de C. in Dixon, 1850).
e overall morphology of the studied fossils is quite
similar to specimens of Turritella asperula Brongniart, 1823
from the “Rupelien” (Oligocene) of the Chambre d’Amour,
in the “Nummulitique” of Biarritz (southwestern Aquitaine
Basin), described and figured by Boussac (1911: 82, 83,
pl. 21, fig. 15 and pl. 22, figs 3, 4). However, the arrange-
ment of spiral ribs looks quite different. In our specimens the
ribs are stronger and more separate in the medium-abapical
part of the whorls, while in Haustator asperulus the ribs are
more regularly distributed over the entire surface of each
whorl. e differences with H. asperulus from the Oligocene
of Iran and Greece, as published in Harzhauser (2004), are
even more marked. Unlike our specimens, H. asperulus does
not have adult whorls with sharp, keeled, spiral ribs. Similar
differences can be established with respect to two specimens
of H. asperulus from the Rupelian of Saint-Hilaire (Pierrefitte,
Essonne, France, MNHN.F.A42164 and A42165), figured
by Lozouet & Maestrati (2012).
Our fossils are, however, very similar to those which Villalta
Comella (1956: 143, 144, pl. 3, figs 1a-1e) assigned to the
species Turritella (Haustator) altavillensis Cossmann & Pissarro
(1900), from the Bartonian of San Román de Basa and Isún
de Basa (Huesca, Jaca Basin, South Pyrenean area). According
227
Gastropods and bivalves from the Pamplona Basin (Eocene)
GEODIVERSITAS • 2018 • 40 (11)
G
C
T
S
R
Q
PON
M
L
K
J
I
H
FEDAB
fig. 8. — Fossils of gastropods from the Eocene (Bartonian-?Priabonian) marly formations of the Pamplona Basin and surrounding areas (Navarre, western Pyr-
enees): A, B, Jponsia sp.: A, IV.26; B, IV.27; C-G, Haustator altavillensis (Cossmann & Pissarro, 1900): C, AD1.2.3; D, AD.21; E, IV.28; F, AD2.2.3; G, AD2.2.2.
H-L, Haustator cf. imbricatarius conoideus (Sowerby J., 1814): H, AD2.1.7; I, IV.29; J, IV.2; K, IV.30; L, AG1.3.5; M-P, Sigmesalia sp.: M, IV.3, apertural view?;
N, AD.25; O, AD1.3.4; P, AD2.1.8; Q-S, Ampullinidae indet.: Q, R, AD.26, apertural and oblique apical views; S, AD.27; T, ?Globularia sp., AD.28, apertural view.
Scale bars: 5 mm.
228 GEODIVERSITAS • 2018 • 40 (11)
Astibia H. et al.
to Villalta Comella (1956), H. altavillensis could be a variety
of H. contractus, which, like our specimens, would differ by
having finer and more granular and irregularly distributed spi-
ral cords, among other distinctive features. However, Villalta
Comella (1956) indicated that, despite the large number of
specimens available, there is a great homogeneity of characters
with no intermediate forms, a fact that could point to the
validity of the species Haustator altavillensis (Cossmann &
Pissarro, 1900). Years later, Puigdefábregas (1975, determi-
nations by Villalta Comella) also mentioned the presence of
H. altavillensis in the Eocene marls of Yebra de Basa, a locality
situated near San Román de Basa and Isún de Basa.
Haustator cf. imbricatarius conoideus (Sowerby J., 1814)
(Fig. 8H-L)
Turritella conoidea Sowerby J., 1814: 109, pl. 51, figs 1-2, 4.
mAteriAl. — Ardanatz Sandstone. 4 specimens from AD sections
(levels unknown). AD2 section: 1 specimen from level AD2.1. AG1
section: 1 specimen from level AG1.2; 1 specimen from AG1.3;
6 specimens from AG1.4. Ilundain Marl Formation, IV section:
33 specimens. All fossils are fragmentary; aperture not preserved.
d
imensions
. — Largest specimen (incomplete, somewhat crushed):
H > 22.0; W = (9.0).
description
Shell medium to large-sized, turretlike, sharply conical; proto-
conch and aperture unknown in the whole sample available;
apical angle of about 16-22 degrees (?); teleoconch with deep
sutures, spire whorls convex-sided and pseudo-imbricated
aspect (abapical part of the whorls protruding with respect
to the adapical part of the next whorl); adult ornamentation
consists of regularly spaced finely granulose spiral cords of at
least three orders; growth-lines opistocirtes. Some morpho-
logical variability in the convexity of the whorls and in the
development of the first abapical rib, generally slightly more
prominent than in other “primary” spirals, was observed.
remArks
e morphology of the specimens from the study area resem
-
bles that of Haustator imbricatarius (Lamarck, 1804), a spe-
cies present in the basins of Paris and London, among other
areas. In H. imbricatarius (specimens from the Lutetian of
Damery [Marne] [Courville et al. (2012), and Chaussy [Val-
d’Oise] and Chaumont-en-Vexin [Oise] [MNHN.F.J03715
and J12228, Cossmann coll.]) considerable variability can
be observed, but the outline of the whorls is generally quite
straight, sometimes even slightly concave, whereas in our fos-
sils it is slightly convex. D’Archiac (1846) cited an incomplete
material of Turritella imbricataria Lamarck, 1804 from the
Eocene of the Port des Basques, near Biarritz (southwestern
Aquitaine Basin). Later Boussac (1911) also cited T. imbri-
cataria in the “Auversien” from the same area, at the site of
Villa Marbella, in the southern part of the Côte des Basques
(Côte des Basques Marls Formation), and Turritella trempina
Carez, 1881 in the “Bartonien inférieur ou Priabonien” from
the northern part of the Côte des Basques. Likewise, two
specimens of the Cossmann collection (MNHN.F.J12119)
collected from the Priabonian of Biarritz and classified as
H. imbricatarius have flat-sided spire whorls, not convex as
in the specimens from Navarre. According to Carez (1881),
H trempinus is distinguished from H. imbricatarius especially
by its narrower shape. e four specimens of H. trempinus
figured by Carez (1881: pl. 4, figs 8-11) have an apical angle of
about 10 degrees. Similarly, one single fossil figured by Boussac
(1911: 51, pl. 11, fig. 17) from Cote des Basques also appears
to have an apical angle of about 10 degrees. By contrast, the
apical angle of seven specimens of Haustator imbricatarius fig-
ured by Courville et al. (2012) from the Lutetian of Damery
(Marne, Paris Basin) is, like in the Eocene fossils of Navarre,
greater, about (14) 16-19 degrees. Cossmann regarded Tu r-
ritella trempina Carez, 1881 as synonymous with Turritella
ataciana d’Orbigny, 1850. According to De Renzi (1971), the
species T. trempina created by Carez in the Eocene (Ilerdian)
from the Conca de Tremp (Catalonia), would be a junior
synonymous of Turritella dixoni Deshayes, 1861.
e fossils from Navarre bear greater similarities to several
specimens of Haustator imbricatarius conoideus (J. Sowerby,
1814) from the Bartonian of Bracklesham Bay and, especially,
of Barton-on-Sea (England) included in the Cossmann col-
lection (MNHN.F.J12173 and J12227). e spiral orna-
mentation is similar in all cases and, although the spire of
the specimens from Bracklesham Bay is less imbricated, the
slightly convex profile of whorls is also similar. Haustator elon-
gatus (J. Sowerby, 1814) from the Bartonian of Barton-on-Sea
(MNHN.F.J12188, Cossmann coll.) also has “imbricated”
whorls and a somewhat convex silhouette, but the shell is
narrower, with a smaller apical angle than in H. imbricatarius
conoideus and in our fossils.
Subfamily pAreorinAe Finlay & Marwick, 1937
Genus Sigmesalia Finlay & Marwick, 1937
type species. — Turritella sulcata Lamarck, 1804 (non Bosc,
1801) by original designation (= synonym of Sigmesalia koeneni
Le Renard, 1994).
Sigmesalia sp.
(Fig. 8M-P)
mAteriAl. — Ardanatz Sandstone. 1 fragmentary specimen from
AD sections (section and level unknown). AD1and AD2 sections:
6 fragments from level AD1.3; 1 fragmentary specimen from level
AD2.1. Ilundain Marl Formation, IV section: 3 fragmentary speci-
mens. In all fossils protoconch and aperture not preserved.
dimensions. — Largest specimen: H > 15.9; W = 7.8 (incomplete
specimen, about 19.0 high complete?).
description
Medium-sized, turretlike, conical; protoconch unknown; apical
angle about 32 degree; adult sculpture with 4 (5) prominent and
229
Gastropods and bivalves from the Pamplona Basin (Eocene)
GEODIVERSITAS • 2018 • 40 (11)
smooth spiral cords; spire whorl sides convex, angled, shouldered,
and more flattish abapically from the second spiral cord; last
whorl with about a dozen ribs down to the base of the shell;
aperture broken, but it expands (effuse) over the columella.
remArks
e assignation of fossils to Pareorinae is difficult when the
aperture is not intact (see Marwick 1957). However, the
general shape of the studied fossils is suggestive of the genera
Mesalia Gray, 1847 and Sigmesalia Finlay & Marwick, 1937.
Squires & Saul (2007) regarded both as congeneric forms.
e studied specimens can be compared to the species
Sigmesalia variabilis Defrance, 1828 from the Bartonian of
Jaignes (Seine-et-Marne, Paris Basin), which also exhibits four
spiral cords (Cossmann & Pissarro 1910: pl. 21, fig. 126-5).
However, in S. variabilis, spire whorl sides are less convex and
cords are weaker (?) than in our specimens. erefore, the latter
are more similar to specimens of S. fasciata (Lamarck, 1804)
figured by Cossmann & Pissarro (1910: pl. 21, fig. 126-9)
from the Lutetian of Villiers-Saint-Frédéric (Yvelines, Paris
Basin), with spiral cords stronger (?) than in S. variabilis.
e resemblance to S. fasciata (Lamarck, 1804) from the
Bartonian of Vendrest (Seine-et-Marne; MNHN.F.J12322,
Cossmann coll.) and to S. variabilis (Defrance, 1828)
from the Bartonian of Le Fayel (Oise; MNHN.F.J12325,
Cossmann coll.) is also remarkable. However, in the latter
two species the shape of whorls is frustoconical, whereas
in our material the shape, abapically the shoulder (the sec-
ond rib), is more angular, having more convex-cylindrical
appearance. S. Sigmesalia koeneni Le Renard, 1994 from the
Lutetian of Damery (Marne, Paris Basin) (Courville et al.
2012: pl. 3, figs 8, 16, 19) and S. solida (Deshayes, 1861)
from the Bartonian of Le Guépelle, Saint-Witz (Val-d’Oise;
MNHN.F.J12353, Cossmann coll.) have more and finer ribs,
and less angular and convex whorl sides. On the other hand,
the strong development of the spiral cords in our fossils bears
a great resemblance to S. pyrenaica (d’ Orbigny, 1850) from
the Ypresian of Arañonet (Catalonia) (MNHN.F.J12189,
Cossmann coll.) and from Fabrezan (Aude), but in both
cases the number of prominent ribs is lower (two or three)
than in our fossils. e small size of the available samples
prevents greater accuracy.
Superfamily cAmpAniloideA Douvillé, 1904
Family AmpullinidAe Cossmann, 1918
Ampullinidae indet.
(Fig. 8 Q-S)
mAteriAl. — Ardanatz Sandstone. 3 specimens from AD sections
(section and level unknown). AG1 section: 1 specimen from AG1.3.
MD1 section: 1 specimen. All specimens fragmentary, protoconch
not preserved, aperture absent or very imcomplete.
dimensions. — Largest specimen: H > 22.0; W = 19.0.
description
Shell medium-sized; globose shape; spire relatively high, with
more than three whorls; shouldered whorls, tabulate and
grooved (shoulder sharpened) last whorl; last whorl inflated,
specially in its middle part; shell surface rather smooth, only
growth lines stand out slightly.
remArks
Ampullinidae includes gastropods that historically many authors
(Cossmann 1888; Glibert 1963, among others) included in
the family Naticidae. Later, Kase (1990) and Kase & Ishikawa
(2003a, b) separated Ampullinidae and Naticidae using both
their soft anatomies and shell morphologies. Recently, Caze
et al. (2011) included coloured pattern features to discriminate
between both families. According to the criteria by Kase & Ishi-
kawa (2003a, b), the relatively high spire and shouldered and
tabulate whorls suggest our fossils may be closer to the family
Ampullinidae. Both families can generally be readily distin-
guished on the basis of their different opening and umbilical
region morphology. Unfortunately, however, the poor preserva-
tion of the studied specimens does not allow further assessment.
e outline of the adapical part of the last whorl of the stud-
ied fossil shells is angular, like in Ampullina Bowdich, 1822, a
genus in which 41 Paleogene species have been described (see
Caze et al. 2011), and, in a lesser extent, like in Crommium
Cossmann, 1888, which includes six exclusively Paleogene
species. In Globularia Swainson, 1840 (Danian-Recent) the
adapical shape of the whorls is generally more rounded.
e presence of Ampullinids in the Eocene of the South Pyr-
enean area was early reported by Cossmann (1898a: 10, pl. 8,
figs 23, 24), who described and figured the species Ampullina
vidali Cossmann, 1898 from the “middle Nummulitic” of Ager
(South Pyrenean area). Farrés (1961) cited in the Bartonian-
Priabonian of Vic numerous species that he assigned to the
genus Natica, today mostly included in Ampullinidae. Martinius
(1995) mentioned the abundance of Amaurellina (Crommium)
intermedia Deshayes, 1833, cf. Amaurellina sp. and Natica sp.
in some biofacies of the Early Eocene of Roda (Aragon). In the
North Pyrenean area, Rouault (1850: pl. 16, figs 2, 3) described
and figured two fossils from the Early Eocene of Bosdarros that
assigned to Ampullaria indet and Natica baylei Rouault, 1850
(=synonym of Ampullina baylei (Rouault, 1850)). e shape
of the columellar lip and the high and acute spire points to the
family Ampullinidae in both cases.
Genus Globularia Swainson, 1840
type species. — Ampullaria sigaretina Lamarck, 1804 by subsequent
designation (Herrmannsen, 1847).
?Globularia sp.
(Fig. 8T)
m
AteriAl
. — Ardanatz Sandstone. One fragmentary specimen
from AD sections (section and level unknown). Protoconch and
aperture not preserved.
230 GEODIVERSITAS • 2018 • 40 (11)
Astibia H. et al.
dimensions. — H = (21.3); W = (18.0).
description And remArks
Shell medium-sized; globose shape (spherical outline); spire
with more than three whorls; whorls tabulate; huge last whorl
of semicircular shape, shell surface smooth, only growth lines
stand out slightly.
e shape of the last whorl is semicircular, like in the
genus Globularia Swainson, 1840, for example in the species
Globularia sigaretina (Lamarck, 1804) from the Lutetian of
Damery (Marne, Paris Basin) (Courville et al. 2012) and the
Bartonian of Antilly (Oise; MNHN.F.J10972, Cossmann
coll.). In the North Pyrenean area, Cossmann (1923: 35,
pl. 3, figs 35-36) cited Ampullina cf. splendida (Deshayes,
1834) (=synonym of Globularia splendida (Deshayes, 1834))
from the Early Eocene of Gan, a locality close to Bosdarros
(southwestern Aquitaine Basin). Villalta Comella (1956)
described two Ampullinidae, Globularia grossa (Deshayes,
1864) and a new species Amauropsina thomasii in the Bar-
tonian marls of Basa Valley (Huesca, Jaca Basin, South
Pyrenean area). A. Amauropsina thomasii Villalta Comella,
1956 exhibits a more compressed shell than the fossil from
Ardanatz. Farrés (1961) cited, among other species, Natica
sigaretina Lamarck, 1804 and Natica acuta Lamarck, 1804
in the Eocene of the Region of Vic (Catalonia), which are
now assigned to the genera Globularia and Crommium,
respectively. Our sample is too small and fragmentary for
an accurate specific assignment.
Clade (Order) HYPSOGASTROPODA
Ponder & Lindberg, 1997
Informal group PTENOGLOSSA (Gray, 1853)
Superfamily epitonioideA Berry, 1910
Family epitoniidAe Berry, 1910
Genus Cirsotrema Mörch, 1852
type species. — Turbo scalaris Linnaeus, 1758 by which kind of
designation? (+ REF).
Subgenus Elegantiscala de Boury, 1911.
type species. — Scalaria elegantissima Deshayes, 1861 by original
designation.
Cirsotrema (Elegantiscala) cf. bouillei
(Tournouër in Bouillé, 1873) n. comb.
(Fig. 9A)
Scalaria bouillei Tournouër in Bouillé, 1873: pl. 6, fig. 1. — Bous-
sac 1911: 35, pl. 3, fig. 5.
mAteriAl. — Ardanatz Sandstone. AD2 section: 1 specimen from
level AD2.1. Protoconch not preserved, aperture broken.
dimensions. — H > 23.0; W = 12.0.
description
Shell medium to large, turriculate; whorls convex-sided with
strong spiral and axial sculpture; 6-7 well marked spiral cords;
raised axial ribs, 15-17 per whorl, foliated, with wavy lamel-
lations and a little spiny, angular shoulder expansion (slightly
hooked at shoulder). Aperture sub-circular.
remArks
e presence of Epitoniidae (= Scalariidae) among the gastro-
pods of the Bartonian marly formations of Navarre was early
mentioned by Ruiz de Gaona (1947), Mendizábal & Ruiz
de Gaona (1949) and Ruiz de Gaona & Colom (1950), who
reported Scalaria sp. from the localities of Ardanatz-Eguesibar,
Tejería (Mendillorri), Altos de Badoztain and Pamplona-Beloso.
is fossil is quite similar to an incomplete specimen from
the Priabonian of Biarritz (MNHN.F.J10160, Cossmann coll.)
assigned to Cirsotrema (Elegantiscala) bouillei (Tournouër in
Bouillé, 1873) n. comb. and three fossils assigned to Scalaria
bouillei, which were described and figured by Boussac (1911:
35, pl. 7, figs 13, 14) from the Auversian (Bartonian) of the
site of Villa Marbella (Côte des Basques Marls Formation,
southwestern Aquitaine Basin), also near the city of Biarritz.
Our specimen also looks like Cirsotrema acuta (Sowerby, 1812)
(Sowerby 1812: 50, pl. 16) from Barton Beds (Barton, High-
cliffe, England). Morton (2018, http://www.dmap.co.uk/fos-
sils/) figured a specimen of this species as Elegantiscala acuta.
Taking the original figure by Sowerby (1812) and Morton’s
photos, C. acuta has a straight profile, not convex, and a
more spiny angular shoulder expansion in the whorls than
our specimen AD2.1.9. In comparison with the fossils from
Biarritz, AD2.1.9 seems to have more developed and perhaps
less numerous axial ribs. Unfortunately, further precision is
not possible with the available material.
Genus Epitonium Röding, 1798
Subgenus Crisposcala de Boury, 1886
t
ype
species
. — Scalaria crispa Lamarck, 1804 by original designation.
Epitonium (Crisposcala) aff. subpyrenaicum
(Tournouër in Bouillé, 1873)
(Fig. 9B-E)
Scalaria subpyrenaica Tournouër in Bouillé, 1873: pl. 3, fig. 2.
Scala (Criposcala) acuminensis [sic] – Villalta Comella (1956: 132,
133, pl. 2, fig. 1 (non Scalaria acuminiensis de Boury, 1883).
m
AteriAl
. — Pamplona Marl Formation: two specimens from EG1
section; one fragmentary specimen from AZ1 section; one incomplete
specimen from IZ1 section. Transition between the Pamplona Marl
Formation and the Ardanatz Sandstone Formation (or Ilundain Marl
Formation): three specimens from BD1 section. Aperture is either
incomplete or not preserved at all in all specimens.
dimensions. — H = (11.1); W = 9.0-17.0.
231
Gastropods and bivalves from the Pamplona Basin (Eocene)
GEODIVERSITAS • 2018 • 40 (11)
A
A
K
J
R
Q
M
P
N
O
L
GF
E
D
CB
IH
fig. 9. — Fossils of gastropods from the Eocene (Bartonian-?Priabonian) marly formations of the Pamplona Basin and surrounding areas (Navarre, western Pyr-
enees): A, Cirsotrema (Elegantiscala) cf. bouillei (Tournouër in Bouillé, 1873) n. comb.: AD2.1.9, apertural view; B-E, Epitonium a. subpyrenaica (Tournouër in
Bouillé, 1873): B, EG1.1.2; C, EG1.1.1; D, BA1.2.4, apertural view; E, BA1.2.3; F, Amaea (Acrilla) pellati De Raincourt & Munier-Chalmas, 1863 n. comb., AZ1.1.1;
G, Amaea (Acrilla) sp.: AD.29; H, Niso sp.: IV.4; I, Sassia (sensu lato) sp. 1, IV.31; J, K, Sassia (sensu lato) sp. 2, AD.33, dorsal and ventral views; L, Metula (Cela-
toconus) sp.: IV.32; M-P, Clavilithes (Clavellofusus) cf. parisiensis Mayer-Eimar, 1876: M, AD2.1.10; N, AD.30; O, AD.31; P, AD2.1.11; Q, R, Paziella (Flexopteron)
sp., AD2.1.12, dorsal and apical views. Scale bars: 5 mm.
232 GEODIVERSITAS • 2018 • 40 (11)
Astibia H. et al.
description
Turriculate shell with shouldered whorls; numerous, thin and
scarcely developed spiral cords; thick, coarse, poly-lamellar
axial ribs, folded back (adaperturally) except in the shoulder,
where a spiny and angular-hooked structure, more marked
in some especially thick axial ribs (varices?), is generated;
surface of axial ribs with a rhomboidal reticular pattern
as a result of wavy lamellations composite structure; deep
sutures; slightly marked umbilical depression; holostomate,
sub-circular aperture.
remArks
Our fossils are quite similar to Epitonium (Crisposcala) acumiense
(de Boury, 1886) from the Bartonian marls of Isún de Basa
(Huesca, Jaca Basin, South Pyrenean area) (Villalta Comella
(1956: pl. 2, fig. 1). ey also bear a great resemblance to
E. (Crisposcala) acumiense from the Bartonian of Acy-en-
Multien (Paris Basin) (Cossmann & Pissarro 1907) and to
E. (Crisposcala) subpyrenaicum (Tournouër in Bouillé, 1873)
(Bouillé 1876: pl. 3, fig. 2) from the Bartonian marls of Côte
des Basques (Biarritz, Côte des Basques Marls Formation,
southwestern Aquitaine Basin). However, both E. (Crispo-
scala) acumiense from Acy-en-Multien and E. (Crisposcala)
subpyrenaicum from Biarritz (figured in Boussac 1911: pl. 21,
fig. 5) have thinner axial ribs than the fossils from Huesca
and Navarre.
Genus Amaea H. Adams & A. Adams, 1853
Subgenus Acrilla H. Adams, 1860
t
ype
species
. — Scalaria acuminata Sowerby G.B. II, 1844 by
original designation.
Amaea (Acrilla) pellati
(De Raincourt & Munier-Chalmas, 1863) n. comb.
(Fig. 9F)
Scalaria pellati De Raincourt & Munier-Chalmas, 1863: 203, 204,
pl. 7, fig. 6a, b.
mAteriAl. — Pamplona Marl Formation: 1 fragmentary specimen
from AZ1 section. Protoconch and aperture not preserved.
dimensions. — H = (20.0); W = (11.5).
description And remArks
Turriculate shell, highly convex whorls separated by deep
sutures, regular cancellate sculpture with squares or, in some
cases, rectangles with their longest axis in the axial direc-
tion. Quite similar to the specimens described as “Scalaria
pellati” by Boussac (1911: 83, p. 21, figs 14, 16, 17, coll.
Pellat) from the Rupelian of the Chambre d’Amour (Biarritz,
southwestern Aquitaine Basin), one of which is the holotype
of this species. e studied specimen also exhibits a general
shape similar to that of two specimens from Barton-on-sea
(MNHN.F.J12482, Cossmann coll.) assigned to Amaea
(Acrilla) reticulata (Solander in Brander, 1766) and to another
two specimens of A. (A.) reticulata from Barton Beds-Barton-
Highcliffe, figured by Morton (2018, http://www.dmap.co.uk/
fossils/). However, in A. (A.) reticulata the ribs are far more
protruding than the spiral cords, whereas in our specimen
the axial and spiral sculptures show a similar development.
Another morphologically close species is A. (A.) dubuissoni
(Vasseur, 1882). A specimen from the Bartonian of Bois-Gouët
(Loire-Atlantique; MNHN.F.J10308, Cossmann coll.) has,
however, a more compressed reticulum in spiral direction,
with a greater number of spiral cords that our specimen.
Amaea (Acrilla) sp.
(Fig. 9G)
mAteriAl. — Ardanatz Sandstone. 1 fragmentary specimen from
AD sections (section and level unknown). AD2 section: 2 fragments
from level AD2.1.
dimensions. — H > 24.0; W = 12.0.
description And remArks
e turriculate shell, convex whorls, finely cancellate sculpture,
with axial ribs slightly more protruded than the spiral cords
and the presence of basal cord, allow these specimens to be
compared to those collected from the Bartonian marls of San
Román de Basa (Huesca, Jaca Basin, South Pyrenean area)
and assigned by Villalta Comella (1956) to Amaea (Acrilla)
reticulata (Solander in Brander, 1766). Villalta Comella
(1956) pointed out the similarity of his specimens to some
figured by Cossmann from the Eocene of Barton-on-Sea
(Hampshire, England). Two specimens from Barton-on-
sea (MNHN.F.J12482, Cossmann coll.) assigned to Amaea
(Acrilla) reticulata also show a general shape similar to our
fossils. However, in these specimens the number of axial ribs
is lower, and the ribs are arranged more regularly and are more
protruding than in the Ardanatz fossils.
Superfamily eulimoideA Philippi, 1853
Family eulimidAe Philippi, 1853
Genus Niso Risso, 1826
type species. — Niso eburnea Risso, 1826 by monotypy.
Niso cf. terebellata (Lamarck, 1804)
(Fig. 9H)
Bulimus terebellatus Lamarck, 1804b: 291, 292.
mAteriAl