Early Priabonian Research Articles

Late Eocene to Early Miocene environments, vegetation and climate in Southeastern France documented by palynology

The Eocene–Oligocene Transition (EOT) is crucial for understanding the climate evolution of the Earth but is poorly documented in the terrestrial domains. A pollen record from the early Priabonian to the late Aquitanian encompassing the EOT was produced for thirty-three locations in Southeastern France. Changes in lowland flora and vegetation were documented based on the shift from dense forests with tropical-subtropical plants to open shrublands rich in xeric plants, paving the way for the future Mediterranean landscapes. Cupressaceae, particularly Tetraclinis, and Ephedra, occupied a proeminent place in the newly structured vegetation. Palaeolimatic fluctuations were quantified using the Climatic Amplitude Method, revealing the fact that the EOT was mainly characterized by a decrease of 7–9 °C in winter temperatures and by an increase in overall temperature and rainfall seasonality. Using the climatostratigraphic approach further improved the regional chronostratigraphy. This climate change occurred during a period and in a region marked by an extensive geodynamic upheaval. This work documents the pathways of some influential marine incursions of the Mediterranean Sea earlier than is usually considered. Finally, the deposition of evaporites in lakes is interpreted as the result of a combination of different factors, including the entrance of marine waters in the terrestrial realm, a decrease in regional rainfall, a decrease in the supply of water by rivers and increased seasonality. Palaeoelevations of nearby mountains were also estimated using pollen grains transported from highlands and reconstructed palaeotemperature of the lowlands.

Challenges in reconstructing the vegetation associated with a late Eocene mammal fauna from Western Europe

Bed TB33, a lacustrine unit within the late Eocene (early Priabonian) How Ledge Limestone, Headon Hill, Isle of Wight, UK, contains a rich mammalian fauna. The previously reconstructed food web included mammalian predators and prey (ground dwelling, scansorial and arboreal; insectivores, frugivores, herbivores and carnivores) and two inferred owls. Unfortunately, the extensive bulk sediment sampling and sieving used to obtain the vertebrate fauna had not yielded any plant fossils other than charophyte gyrogonites. This new work has focused on plant mesofossils and palynofacies in the uppermost horizons of the vertebrate-rich bed aiming to reconstruct the vegetation that hosted the mammals. Other than cysts of Zygnemataceae, phytoplankton are absent. The presence of the aquatic plants Azolla and Salvinia on the lake is documented by megaspores and microspore massulae. The palynomorphs are dominated by algal cysts, Azolla microspore massulae fragments and two morphologies of trilete fern spores. These data document a depositional setting in a lake with abundant free-floating Azolla or Salvinia and with a margin vegetation dominated by ferns. The data support one of our previous inferences that the arboreal mammals were brought to the site from some distance away by predators. However, the challenge to fully reconstruct the mammalian habitats remains.

Earliest fossil pollen records of endemic African Sclerosperma palms and the palaeoecological aspects of the genus

Palm diversity in present-day Africa is much less than in other tropical regions such as the Americas and Southeast Asia but comprises several endemic genera, including Sclerosperma. The origin and evolution of this small Arecaceae genus are still enigmatic, and every new fossil discovered helps fill the void in its palaeophytogeographic history. In this article, we report five different pollen morphologies assigned to Sclerosperma from the earliest Late Eocene (early Priabonian) of southeast Kenya, Africa. These pollen grains represent the earliest fossil records of Sclerosperma so far and add a new geographic region and time slot to the palaeophytogeographic history of this genus. The morphological variability observed in the fossil pollen suggests that the diversification within Sclerosperma was already underway by the onset of the Priabonian, c. 37 Ma. Detailed analysis of the distribution of the three extant Sclerosperma species shows that this genus occurs only under Equatorial/Tropical climates with MTCM ≥18 °C, such as fully humid Rainforest (Af), Monsoonal (Am), and winter dry Savannah (Aw) climates. Sclerosperma is also conservative when it comes to vegetation biomes and only occurs in three different but closely related biomes, the Tropical & Subtropical Moist Forests Biome, the Tropical & Subtropical Grasslands, Savannahs & Shrublands Biome, and the Mangroves Biome. No current outliners pinpoint to a wider ecological tolerance of this genus in the geological past. This suggests Sclerosperma to be an exceptionally reliable taxon for palaeoclimate estimations and when assigning palaeofloras to major vegetation biomes.

Priabonian (upper Eocene) larger foraminifera from the Helvetic Nappes of the Alps (Western Switzerland): new markers for Shallow Benthic zones 19-20

Here, we revise and update the biostratigraphy of larger foraminiferal assemblages in three sections of the Priabonian Sanetsch Formation in the Helvetic Nappes of theWestern Swiss Alps: The SexRouge (SE) and the Sanetsch Buvette (SA) sections in the Wildhorn Nappe Complex, and the Col des Essets (ETS) section in the most external Morcles Nappe. In the SE and SA sections, the Tsanfleuron and most of the Pierredar Limestone members of the formation are assigned to SBZ 19 (early Priabonian), while the uppermost part of the formation is assigned to SBZ 20 (late Priabonian). In the external ETS section the entire Sanetsch Formation contains assemblages characteristic of SBZ 19, suggesting an earlier, middle-late Priabonian onset of the hemipelagic Stad Formation (Globigerina Marls). Since it was established in 1998, the Shallow Benthic Zones (SBZ), a biozonation based on larger foraminifera, has been a useful tool in the biostratigraphy of the Paleogene. Biozonation proposals for the late middle-late Eocene are based mainly in biometrical subdivision of lineages of nummulitids and orthophragmines,which requiresmeasurements in oriented sections of isolated specimens. Here, we define previously unreported taxa from the Sanetsch Formation, which are considered characteristic for the Priabonian. They are easy to identify in random sections and thus useful biostratigraphical markers.We also describe a new orthophragminid genus, Virgasterocylina n. gen. (Orbitoclypeidae) characterized by the presence of rods, radial thickenings of calcite along ribs; a new species of Rotorbinella, R. epardi n. sp., and a new genus and new species of difficult suprageneric attribution, Sanetschella indeprensa n. gen., n. sp. We add the new taxa to the larger foraminiferal association characterizing the Priabonian (SBZ 19-20). The revision of the literature, together with our own sample collections revealed that these new taxa occur in Priabonian rocks from different basins in the western Tethys. Virgasterocylina n. gen. also occurs in the Caribbean bioprovince in the middle and upper Eocene. In the western Tethys, Virgasterocylina ferrandezi is subdivided into two subspecies, V. f. ferrandezi (Ozcan and Less) and V. f. lessi n. ssp., which characterize the SBZ 19 and 20 biozones respectively.

New Middle Eocene proboscidean from Togo illuminates the early evolution of the elephantiform-like dental pattern.

Africa has played a pivotal role in the evolution of early proboscideans (elephants and their extinct relatives), yet vast temporal and geographical zones remain uncharted on the continent. A long hiatus encompassing most of the Eocene (Ypresian to the Early Priabonian, around 13 Myr timespan) considerably hampers our understanding of the early evolutionary history of the group. It is notably the case with the origin of its most successful members, the Elephantiformes, i.e. all elephant-like proboscideans most closely related to modern elephants. Here, we describe a proboscidean lower molar discovered in Lutetian phosphate deposits from Togo, and name a new genus and species, Dagbatitherium tassyi. We show that Dagbatitherium displays several elephantiform dental characteristics such as a three-layered Schmelzmuster, the presence of a mesoconid, transversely enlarged buccal cusps and the individualization of a third lophid closely appressed to a minute distal cingulid. Dagbatitherium represents a stem Elephantiformes, pushing back the origin of the group by about 10 Myr, i.e. a third of its currently known evolutionary history. More importantly, Dagbatitherium potentially unlocks the puzzle of the origin of the unique elephantiform tooth crown organization by bridging a critical temporal and morphological gap between early bunodont incipiently bilophodont proboscidean taxa and more derived elephantiforms.

Reassessment of the age and depositional environment of the Kırkgeçit Formation based on larger benthic foraminifera, NW Elazığ, Eastern Turkey

The middle-upper Eocene Kırkgeçit Formation, the fossil content of which is the subject of this study, is deposited in a back-arc basin controlled by block-faulting. The Kırkgeçit basin is interpreted as being formed under an extensional regime related to convergence between the Anatolian plate in the north and the Arabian plate in the south. The aim of this study is to reassess the age and depositional environment of the Kırkgeçit Formation by using detailed biometric analysis data obtained from the reticulate Nummulites and determinations of other larger benthic foraminifera (LBF) in the unit. For this purpose, two sections were measured from the latest Bartonian-Priabonian aged unit. Biometric data of the Nummulites hormoensis and Nummulites fabianii from the Kırkgeçit Formation exposures in the northwest of Elazığ has been presented for the first time. In general, Nummulites fabianii has robust test with thick walls, while Nummulites hormoensis has elongated test with thinner walls in relation to the increase of water depth. The change in embryon size of these reticulate Nummulites has been considered an important indicator for evolution and biostratigraphy. Nummulites hormoensis marks latest Bartonian to early Priabonian (SBZ 18) while Nummulites fabianii is a marker for middle-late Priabonian (SBZ 19-20). The Kırkgeçit Formation in the study area was previously dated as late Lutetian-Priabonian based on LBF of it. However, by considering the LBF determined in this study, the latest Bartonian-Priabonian age was assigned to unit. Based on the paleontological and sedimentological features, the Kırkgeçit Formation has been interpreted as a unit deposited on the inner and middle parts of a shallow ramp.

Late Eocene (Priabonian) dinoflagellate cysts from Primorsky Quarry, southeast Baltic coast, Kaliningrad Oblast, Russia

Forty-seven rock samples from the stratotypes of upper Paleogene formations - Prussian, Palvé and Kurshskaya formations – are collected from the biggest amber deposit worldwide (Primorsky quarry, Kaliningrad oblast, SE Baltic coast), and have been palynologically analyzed. The presence of age-diagnostic dinoflagellate species has allowed us to refine and update the previously questionable age of regional lithostratigraphic units. Based on the presence of Rhombodinium perforatum, the “Upper Wild Earth” and “Upper Blue Earth” members of the Prussian Formation correspond to the early Priabonian (Late Eocene) Rhombodinium perforatum Zone. The overlying “Upper Quicksand” and “White Wall” members of the Prussian Formation contain the key-species Thalassiphora reticulata, and are correlated with the late Priabonian T. reticulata Zone. The overlying Palvé Fm (“Green Wall”), comprises a dinoflagellate cyst assemblage very close to that recorded from the Prussian Formation, and also corresponds to the T. reticulata Zone, late Priabonian. The lower part of the Kurshskaya Formation – “Chocolate clays” and lower “Brown sands” members, contain an impoverished dinoflagellate cyst assemblages as a result of significant environmental changes. However, the common presence of Areosphaeridium diktyoplokum and Glaphyrocysta semitecta, along with an absence of early Oligocene key-species Wetzeliella gochtii or Chiropteridium galea, and pollen key-species Boehlensipollis hohli or Aglaoreidia cyclops, suggest the lower Kurshskaya Formation can be correlated with the latest Eocene, and very close to the Eocene/Oligocene boundary. Based on the revised stratigraphic ages presented here, we suggest an important regional marine transgression occurred during the Priabonian, which allowed the direct marine connection between the NW European Basin and Peri-Tethys via the Polish-Luthuanian Seaway. This was then followed by a regression at the end of Priabonian that culminated in a transition to continental sedimentation in the early Rupelian. A new dinoflagellate cyst species Oligokolpoma balticus sp. nov. is formally described.

(Bio)stratigraphic overview and paleoclimatic-paleoceanographic implications of the middle-upper Eocene deposits from the Ica River Valley (East Pisco Basin, Peru)

The Eocene sediment successions of the East Pisco Basin (southern Peru) host an exceptionally rich and well-preserved assemblage of vertebrate fossils. However, due to the dearth of geochronological and biostratigraphic controls as well as of stratigraphic correlations, our understanding of these rocks and their fossil content remains elusive.This paper provides a comprehensive calcareous nannofossil, diatom, and silicoflagellate biostratigraphic framework for the Eocene strata exposed at four localities along the Ica River Valley, permitting a robust chronological calibration of the marine vertebrate fauna entombed therein and a better definition of important appearance/ extinction events. The Paracas Formation, deposited directly on top of the Proterozoic and Paleozoic rocks of the crystalline basement, is formed by a siliciclastic-bioclastic sand-sized deposit (Los Choros member) and calcareous-terrigenous siltstone (Yumaque member) that was deposited from the Lutetian (47.8–41.2 Ma) through the Bartonian (41.2–37.7 Ma) to the early Priabonian (37.7–33.9 Ma). The unconformably overlying Otuma Formation consists of a basal sandstone, followed by calcareous siltstone intercalated by diatomite layers towards the top. In the study area, the Otuma Formation is Priabonian in age and is truncated at the top by an unconformity at the base of the overlying Miocene Chilcatay Formation. Due to the angular nature of the unconformity, the upper Otuma strata reach the Oligocene elsewhere.Average sedimentation rates range from 17 to 24 m/My in the Yumaque member of the Paracas Formation and increase to 147–170 m/My in the Otuma Formation. The microfossil assemblages witness a coastal setting with warm-temperate conditions for the Paracas Formation that become slightly cooler (though still temperate) in the upper Otuma Formation. Diatomaceous layers in the upper Otuma Formation indicate an overall increase in nutrient availability, which could reflect the global reorganization of ocean currents at the Eocene-Oligocene transition. However, the taxonomic composition of the diatom assemblage suggests seasonal rather than persistent upwelling conditions.

Stratigraphic and Tectonic Setting of the Liguride Units Cropping Out along the Southeastern Side of the Agri Valley (Southern Apennines, Italy)

This paper shows the main results of a multidisciplinary study performed along the southeastern sector of the Agri Valley in Basilicata (Southern Italy), where Cenozoic units, crucial for constraining the progressive evolution of the Southern Apennine thrust and fold belt and, more in general, the geodynamic evolution of the Mediterranean area are widely exposed. In particular, we aimed at understanding the stratigraphic and tectonic setting of deep-sea, thrust-top Cenozoic units exposed immediately to north of Montemurro, between Costa Molina and Monte dell’Agresto. In the previous works different units, showing similar sedimentological characteristics but uncertain age attribution, have been reported in the study area. In our study, we focussed on the Albidona Formation, pertaining to the Liguride realm, which shows most significant uncertainties regarding the age and the stratigraphic setting. The study was based on a detailed field survey which led to a new geological map of the area. This was supported by new stratigraphic, biostratigraphic and structural analyses. Biostratigraphic analysis provided an age not older than the upper Ypresian and not younger than the early Priabonian. Recognition of marker stratigraphic horizons strongly helped in the understanding of the stratigraphy of the area. The study allowed a complete revision of the stratigraphy of the outcropping Cenozoic units, the recognition of until now unknown tectonic structures and the correlation between surface and subsurface geology.

Insights into the Cenozoic geology of North Beirut (harbour area): biostratigraphy, sedimentology and structural history

The biostratigraphy and sedimentology of the outcrops and bedrock recently exposed in archaeological excavations around the harbour area of Beirut (~5 km²) unlock the geological and structural history of that area, which in turn are key to understanding the hydrocarbon and hydrogeological potential of the region. A key location (Site 2) of a studied outcrop section and newly uncovered bedrock is on the northern foothill cliff of East Beirut (Achrafieh). The outcrop section of carbonates is of Eocene beds overlain by conformable Miocene beds. The excavation of the slope bordering the outcrop uncovered a bedrock section of an early Pliocene shoreline of carbonate/siliciclastic sands at its base and topped by a beach-rock structure. The early Pliocene age of the shoreline section is dated by an assemblage of planktonic foraminifera that includes Sphaeroidinellopsis subdehiscens, Sphaeroidinella dehiscens and Orbulina universa. The Eocene carbonates of Site 2 extend the coverage of the previously reported Eocene outcrops in the harbour area. They form a parasequence of thin-bedded, chalky white limestones that includes the youngest fossil fish deposits in Lebanon (Bregmaceros filamentosus). The deposits are dated as early Priabonian by their association with the planktonic foraminiferal assemblage of Porticulasphaera tropicalis, Globigerinatheka barri, Dentoglobigerina venezuelana, Globigerina praebulloides, Turborotalia centralis and Borelis sp. The Middle Miocene carbonates that conformably overlie the early Priabonian, parasequence include a planktonic foraminiferal assemblage of Globigerinoides trilobus, Orbulina universa and Borelis melo. Elsewhere, in the harbour area, the preserved Eocene limestones are also overlain by conformable Miocene carbonate parasequences of Langhian-Serravallian age. Younger argillaceous limestone beds of the Mio/Pliocene age occur in the eastern central part of the harbour area and enclose an assemblage of Truncorotalia crassaformis, Globorotalia inflata and Orbulina universa. The three markers of old and recently raised structural blocks in the harbour area are a Lutetian/Bartonian marine terrace in the south west corner, a lower Pliocene shoreline carbonate section in the north east side and a Holocene raised beach of marine conglomerates in the north east corner of the area. The locations of these paleo-shorelines, less than 2 km apart, indicate a progressive platform narrowing of North Beirut since the Paleogene. This study underpins the geological complexity of the region and contributes to understanding the underlying geology, which will be needed for future regional archaeological, hydrocarbon and hydrogeological exploration.

Filling a gap in the proboscidean fossil record: a new genus from the Lutetian of Senegal

AbstractA long hiatus encompassing most of the Eocene (end of the Ypresian to the early Priabonian) breaks up the proboscidean evolutionary history, which is otherwise documented by a rich fossil record. Only two post-Ypresian localities from West Africa (Mali and Senegal) have yielded scarceMoeritherium-like dental remains. Here, we study one of these remains from Senegal and name a new genus and species,Saloumia gorodiskii. This taxon, confidently mid-Lutetian in age, evokesMoeritheriumand elephantiforms with its wrinkled enamel, lack of centrocrista, and strong lingual cingulum. However, due to its pronounced bunodonty, which departs from the bunolophodonty of bothMoeritheriumand elephantiforms, we cannot exclude the possibility thatSaloumiadocuments an early experiment in dental diversity among Paleocene–Eocene proboscideans, without direct relationships with later proboscideans.UUID:http://www.zoobank.org/0b6b83f8-817d-498c-a672-8ffa8f81a978

Mystacodon selenensis, the earliest known toothed mysticete (Cetacea, Mammalia) from the late Eocene of Peru: anatomy, phylogeny, and feeding adaptations

Mystacodon selenensis Lambert, Martínez-Cáceres, Bianucci, Di Celma, Salas-Gismondi, Steurbaut, Urbina & Muizon, 2017 is a toothed mysticete that represents the earliest member of the suborder in the current state of knowledge. Its holotype is a relatively complete skeleton from the upper Eocene (early Priabonian, c. 36.4 Ma) Yumaque Member of the Paracas Formation from the southern coast of Peru. The thorough description of this specimen is presented here and reveals numerous similarities with the contemporaneous basilosaurids including the retention of an innominate that originally articulated to the unpreserved hind limb. However, several characters of M. selenensis clearly relate this taxon to the mysticetes, such as the large palate with a dorsoventrally flattened rostrum, the posterior extension of the palate with an infraorbital plate of the maxilla, the shortening of the premaxillary part of the rostrum, the zygomatic process of the squamosal being closely apposed to the postorbital process of the frontal, and the humeral head being oriented more proximally than posteriorly. A parsimony analysis retrieves Mystacodon as the earliest diverging branch of the Mysticeti with no close phylogenetic relationship with Llanocetus the second oldest known mysticete (c. 34.2 Ma). The dental formula of M. selenensis is that of basilosaurids (I 3/3, C 1/1, P 4/4, M 2/3). The anterior teeth (incisors and canine) are distinctly proportionally smaller than in basilosaurids, whereas the cheek teeth are very close in relative length, but are relatively larger than in most other toothed mysticetes (except Coronodon). The large cheek teeth of Mystacodon suggest a raptorial feeding strategy, probably assisted with some degree of suction, as indicated by the large size of the palate. The anterior teeth of the holotype display a subhorizontal apical wear facet and the cheek teeth a moderately sloping wear surface, differing from the subvertical attrition facets of basilosaurids. This pattern suggests an efficient dental abrasion resulting from feeding upon abrasive food items or/and from the ingestion of sediment during prey capture, which could indicate some degree of bottom feeding. On the forelimb, the size and orientation of the acromion, the great length of the deltopectoral crest, the massiveness of the olecranon of the ulna, and the strong radial anterior process indicate powerful shoulder movements, which suggest an active use of the forelimb when foraging for food on the sea floor. The robustness of digits and the pachyosteosclerosis of ribs with pestle-like distal end corroborate such a scenario. Mystacodon selenensis represents a first step in the evolutionary history of feeding adaptations of early mysticetes; the latter are likely to have experimented an abundant set of feeding strategies and were probably very eclectic in prey choice and capture before hyperspecialized filter feeding became widespread in the suborder.

Middle-Late Eocene marine record of the Biga Peninsula, NW Anatolia, Turkey

The Eocene shallow marine deposits marking the first marine incursion in the Biga Peninsula (NW Turkey) after the collision of the Sakarya and Anatolide-Tauride plates were investigated based on paleontological, litho- and chrono-stratigraphic data. Larger Benthic Foraminifera (LBF) from patchily distributed outcrops were studied in order to i) revise the stratigraphy of Eocene shallow marine units, and ii) establish a modern biostratigraphic setting and a correlation scheme. The Sevketiye Formation (Fm.) is herein defined as a predominantly shallow marine clastic deposit with subordinate carbonates overlying the Camlica metamorphic rocks, and passing laterally to the Sogucak Fm., a carbonate unit that is widely represented in the Thrace Basin. The record of alveolinids, primitive developmental stages of heterosteginids, and orthophragminids in the Sevketiye Fm. suggests that this formation is part of the Shallow Benthic Zones (SBZ) 16?/17 (Late Lutetian?/Early Bartonian), SBZ17?/18 and SBZ19A (Early Bartonian/earliest Priabonian). The Sogucak Fm., which overlies the Eocene volcanics, on the other hand, yielded advanced developmental stages of heterosteginids, Spiroclypeus sp. and Nummulites fabianii lineages, implying a younger marine incursion during the Late Eocene (earliest Priabonian; SBZ19A). A drastic shift in the depositional regime is marked amid Priabonian by the deposition of deep-marine clastics and volcanoclastics of the Ceylan Fm. In conclusion, the Eocene Sea transgressed first Gokceada (in the Aegean Sea) during the Late Lutetian, then reached the Biga and Gelibolu peninsulas in the Bartonian, and finally led to the widespread deposition of carbonate and siliciclastic rocks in the Biga Peninsula and the Thrace Basin during the Late Bartonian and Priabonian.

Discovery of the oldest European ruminant in the late Eocene of Bulgaria: Did tectonics influence the diachronic development of the Grande Coupure?

We describe the oldest known European ruminant, Bachitherium thraciensis sp. nov., from late Eocene (latest Bartonian or early Priabonian) strata in Bulgaria. The new specimen, which possesses the most primitive dental morphology known in the Bachitheriidae family, predates its western European relatives by at least 4.5 Myr. The discovery suggests that ruminants dispersed into Europe in a series of east to west waves, preceding and following the Eocene–Oligocene boundary. Probably originating from Asia, the oldest ruminant (reported here) migrated into southeastern Europe. During a second wave, comprising the Grand Coupure dispersal event, ruminants moved into western Europe at the Eocene–Oligocene boundary. A third wave composed by Bachitheriidae and Tragulidae arrived in western Europe, 2 Myr later, in the earliest Oligocene. The origin of this east to west diachronism was probably facilitated by orogenesis that, episodically, allowed dispersal of ruminants from Asia, through southeastern Europe, and into western Europe, in what we herein term the “Bachitherium dispersal event”. However, none of the abundant perissodactyl fauna from southeastern Europe migrated to western Europe during this time, because, like their relatives in central Asia, they may not survive to terminal Eocene cooling and aridity.

Bartonian orthophragminids with new endemic species from the Pirkoh and Drazinda formations in the Sulaiman Range, Indus Basin, Pakistan

The Pirkoh and Drazinda formations in the Sulaiman Range, central Pakistan, yielded assemblages of (early) Bartonian orthophragminids, characterized predominantly by discocyclinids with a significant number of species probably endemic to Indian Subcontinent. The rarity of Asterocyclina and the absence of Orbitoclypeus and Nemkovella are noteworthy. Ten species of Discocyclina Gümbel and two species of Asterocyclina Gümbel, referable to the Shallow Benthics Zone (SBZ) 17 are described for the first time from Pakistan. The discocyclinids, i.e. Discocyclina praeomphalus, D. sulaimanensis, D. kutchensis, along with the new taxa established here, D. zindapirensis sp. nov., D. rakhinalaensis sp. nov., and D. pseudodispansa sp. nov., seem to be confined to the Indo-Pakistani region (Eastern Tethys). The Discocyclina dispansa, D. discus, D. nandori, and D. augustae lineages known from Western Tethys are also common in the Indian Subcontinent, as are asterocyclinids, such as Asterocyclina sireli and A. stellata. The upper part of the Drazinda Formation (‘Pellatispira beds’), referable to latest Bartonian and/or the early Priabonian, is poor in orthophragminids and is characterized by the occurrence of reticulate Nummulites, Heterostegina, Pellatispira and Silvestriella. The records of ‘Lepidocyclina of Caribbean affinity’ with large embryons from the Eocene of the Indian Subcontinent correspond to misidentified Discocyclina discus.

Reconstruction of a saline, lacustrine carbonate system (Priabonian, St-Chaptes Basin, SE France): Depositional models, paleogeographic and paleoclimatic implications

A 220-m thick carbonate-dominated succession has been deposited in shallow-water, saline lake environments during the early to middle Priabonian (MP17A-MP18 mammal zones) in the Saint-Chaptes Basin (south–east France). The palaeoenvironmental, paleoclimatic and palaeogeographic significance of such saline lake carbonates has been deciphered on the basis of a multi-proxy analyses including: 1) depositional and diagenetic features; 2) biological components (molluscs, benthic foraminifera, characean gyrogonites, spores and pollens); 3) carbon and oxygen stable isotopes; 4) trace elements; and 5) clay mineralogy. Five stages of lacustrine system evolution have been identified: 1) fresh-water closed lake under dry climate (unit U1); 2) fresh to brackish water lacustrine deltaic system with a mixed carbonate-siliciclastic sedimentation under relatively wet climatic conditions (unit U2); 3) salt-water lacustrine carbonate system under humid climatic setting (unit U3); 4) evaporitic lake (unit U4); and 5) closed lake with shallow-water carbonate sedimentation under subtropical to Mediterranean climate with dry seasons (unit U5). Upper Eocene aridification is evidenced to have started as early as the earliest Priabonian (unit U1: MP17A mammal zone). A change from humid to dryer climatic conditions is recorded between units U3 and U4. The early to middle Priabonian saline lake is interpreted as an athalassic (inland) lake that have been transiently connected with neighboring salt lakes influenced by seawater and/or fed with sulfates deriving from recycling of evaporites. Maximum of connection with neighboring saline lakes (Mormoiron Basin, Camargue and Central grabens, Hérault Basin) likely occurred during unit U3 and at the base of unit U5. The most likely sources of salts of these adjacent basins are: 1) Triassic evaporites derived from salt-diapirs (Rhône valley) or from paleo-outcrops located east of the Durance fault or offshore in the Gulf of Lion; or 2) marine incursions from the south, through Paleogene grabens in the Gulf of Lion.

A new genus and new species of decapod crustacean (Decapoda: Brachyura: Panopeidae) from the early Priabonian (Late Eocene) of the central Pyrenees of Huesca (Aragón, Spain), with remarks on its habitat and ecology

A new genus and new species of decapod crustacean (Decapoda: Brachyura: Panopeidae) from the early Priabonian (Late Eocene) of the central Pyrenees of Huesca (Aragón, Spain), with remarks on its habitat and ecology

First record of the mangrove palm Nypa from the northeastern Ebro Basin, Spain: with taphonomic criteria to evaluate the drifting duration

Fossil fruits pertaining to the mangrove palm genus Nypa Steck, (Arecaceae, Arecales) were collected from a new plant-bearing assemblage in the Arguis Formation (Fm.), northeastern Ebro Basin (Arguis, Huesca Province, Spain). This formation is Bartonian to early Priabonian in age and comprises pro-delta and carbonate platform deposits. The new assemblage consists of nine specimens of fossil Nypa fruits and one monocotyledon leaf fragment. Over half of these fossil fruits are nearly-complete (i.e. with preserved mesocarps) while the other represent endocarps. From the point of view of morphology and size they resemble other European records of this genus. The type of remain preserved (fruits or endocarps), presence of abrasion, Teredo borings and sedimentary facies provide criteria to infer contrasting lengths of transport (drifting). However, they indicate in all cases that these fossil fruits were afloat in seawater for a considerable time. The discovery of Nypa fruits suggests a tropical-subtropical climate in the area, as well as the presence of a coastal environment and littoral forests during deposition. This interpretation corroborates previous findings from the nearby Eocene outcrops of the Catalan Central Depression (Eastern Pyrenees range).

New fossils of Hyaenodonta (Mammalia) from the Eocene localities of Chambi (Tunisia) and Bir el Ater (Algeria), and the evolution of the earliest African hyaenodonts

We present and describe new fossils from the Eocene North African localities of Chambi (Tunisia; late Ypresian or early Lutetian) and Bir el Ater (Algeria; latest Bartonian or earliest Priabonian). The specimens from Chambi allow recognizing two recently described hyainailourines: Furodon crocheti and Parvavorodon gheerbranti; these taxa were previously known from the Gour Lazib area (Algeria; late Ypresian or early Lutetian). The new material from Tunisia includes a fragmentary dentary of Parvavorodon that substantially supports the hyainailourine status of this genus and represents the oldest dentary fragment presently known for a juvenile of Hyaenodonta in Africa. The presence of Furodon and Parvavorodon in Chambi strengthens support for the hypothesis of contemporaneity of the Eocene Gour Lazib and Chambi mammal-bearing localities. In addition, the find of a typical teratodontine fourth premolar in Chambi testifies to the presence of a small representative of this group. The fossil record in Bir el Ater is scarcer than in Chambi. However, we recognize specimens attributable to a hyainailourine and a teratodontine. The latter is referred as Masrasector cf. ligabuei, and is the oldest record for this genus. We tentatively identify a modification of the hyaenodont fauna in the Maghreb after the “Early Eocene Climatic Optimum” (EECO). This faunal change might be related to the decrease of the global temperature after the EECO event. It appears contemporaneous of a drastic replacement in the composition of the mammal faunas in Africa. Finally, the end of the Eocene (Priabonian) shows an increase in the subfamilial richness amongst hyaenodonts.

Eocene dinoflagellate cysts from the Sołokija Graben (Roztocze, SE Poland): biostratigraphy and palaeoenvironment

The Solokija Graben is a tectonic structure in Roztocze, the south-eastern Poland, unique by its infill with the Eocene marine strata. The over 40 metres thick sandy succession is the only well-dated palaeontologically trace of Eocene marine transgression at Roztocze being virtually the only remains of the Eocene epicontinental sea in this part of Poland: the surrounding area is devoid of coeval marine strata, which were eroded. This makes the Solokija Graben succession crucial for the palaeogeography reconstruction of the south-eastern Poland during Eocene as well as the tectonic history of this region. For its precise age determination, the over 30-m-thick succession of loamy sands that fill the Solokija Graben in a borehole at Leliszka and a 4-m-thick one at Łaszczowka were sampled for dinoflagellate cysts. Samples from Łaszczowka are barren, whereas the ones from Leliszka contain rich and taxonomically diverse assemblages. Their biostratigraphical interpretation confirms previous results suggesting the Bartonian age of the most of the Solokija Graben succession; the postulated Priabonian age of its non-calcareous part was documented in its uppermost part only. Palynological record allows reconstruction of sedimentary setting of the Leliszka succession. Basal part of the Bartonian was deposited in a shallow but relatively vast marine basin characterized by normal salinity and high energetic hydrodynamic conditions. Subsequently, marine basin underwent gradual shallowing and temporal cease of sedimentation. During the late Bartonian basin became brackish. A short-lasting early Priabonian marine basin was characterized by shallow marine conditions; it became brackish during its final stage. Comparison with neighbouring Eocene deposits of the epicontinental and Carpathian basins shows that the marine basin at Roztocze was presumably connected with both during Bartonian, and separated from the Carpathian one during early Priabonian. Factors controlling seaways pattern of the Roztocze basin were either eustatics and substratum tectonic movements, the former dominating during Bartonian, and interfingering with uplift of the Meta-Carpathian Swell during early Priabonian.