International seminar series 2019-03-13T12:19:58+00:00

International Seminar of Paleontology,
Evolution, Paleoecosystems, and Paleoprimatology

This seminar series presents high level research works in relation to the study of life in deep time. The topics include paleobiodiversity, paleobiology, paleoecology, paleoanthropology, paleogenetics, but can also come from related fields, such as geology, prehistory, environmental sciences, conservation biology, etc.

This seminar is fed by the national and international collaborative networks of PALEVOPRIM. It is open to the staff and students of the University of Poitiers within the limits of seat availability.

Current (macro-) palaeontological research in Greece

Speaker: Dimitri S. KOSTOPOULOS, Professor at the School of Geology, Aristotle University of Thessaloniki, Greece

Date: March 8th 2019 – 14:00 pm
Location: Room 410 , bat. B35 (3rd floor, North wing), University of Poitiers

Summary: Palaeontological Research in Greece, especially that regarding macrofossils, has a long tradition that goes back to the times of A. Gaudry and C. Arambourg. Modern Greek (macro-)palaeontological research is mainly carried out by the Laboratories of Palaeontology of the Geological Departments in Athens, Thessaloniki and Patras, as well as by the only two National Local Natural History Museums in Crete and in Lesvos islands. This talk presents the most current and interesting findings from field and lab activities of these institutions focusing on fossil vertebrates.

Dimitri S. Kostopoulos is a vertebrate paleontologist, and notably a worldwide known specialist of the taxonomy and phylogeny of Artiodactyla (bovids, cervids, giraffids, suids…). D. S. Kostopoulos is involved in many international projects in Greece and abroad. He collaborates for almost a decade with Palevoprim members on a an early Pleistocene site in northern Greece. D. S. Kostopoulos is also piloting a new Master program “Paleontology/Geobiology” in Greece.

The large ungulates from the Mio-Pliocene of the Lake Chad Basin: paleobiogeographical implications and prospects

Speaker: Likius ANDOSSA, University of Moundou & Department of Paleontology, University of Ndjamena, Chad

Date: April 26th 2018 – 1:30 pm
Location: Room 410 , bat. B35 (3rd floor, North wing), University of Poitiers

Summary: The northern part of the Lake Chad Basin is particularly interesting in terms of paleontological remains. The Mission Paléoanthropologique FrancoTchadienne has intensely surveyed the basin since 1994. This resulted in discovering important fossil sites covering the interval 3.5 Ma-7 Ma, as well as ancient hominid remains (Australopithecus bahrelghazali, Sahelanthropus tchadensis). These hominids are associated to a large quantity of fossil mammals, among which the relatively scarce remains of rhinocerotids, giraffids, and camelids. The analysis of these families allowed identifying nine taxa, including a new one. The recognition of large ungulate species close to Eurasian forms in the Chadian upper Miocene and the lower Pliocene implies intercontinental relations during the corresponding ages. In addition to this work on the fossil fauna diversity, the Chadian paleontology team have organized fieldwork missions on a yearly basis by since 2006. These researches demonstrate that the sites of the Lake Chad Basin kept all their potential for major discoveries. A future approach would consist in taking advantage of studying the Chad extant environments for interpreting the fossil environments. Alongside these contributions, conservation and diffusion of scientific knowledge are also part of a long-run partnership between the Department of Paleontology (University of N’Djamena), the National Center of Research for Development, and the laboratory PALEVOPRIM.

LIKIUS ANDOSSA is one of the two first paleontologists from Chad. He is currently the chancellor of the University of Moundou. His research expertise extends to several groups of African large ungulates that are key elements of the ecosystems in which the first representatives of humankind lived.

Early Oldowan occupations and environmental factors: Interrelations and evolution based on archeological data from the Shungura Formation (Lower Omo Valley, Ethiopia)

Speaker: Tiphaine MAURIN, UMR 5199 PACEA – de la Préhistoire à l’Actuel : Culture, Environnement et Anthropologie Université de Bordeaux

Date: April 26th 2018 – 1:30 pm
Location: Room 410 , bat. B35 (3rd floor, North wing), University of Poitiers

Summary: In the Shungura Formation, the appearance of stone knapping behavior co-occurs with the appearance of the early Oldowan and concentrate on a relatively short time interval (Member F and lower part of Member G, from 2.3 Ma to 2.0 Ma), although fossil hominids are recorded throughout the full sequence (from 3.6 Ma to 1.0 Ma). A multiscale approach was developed in order to investigate the interrelations between the evolution of early Oldowan occupations and environmental factors. It allows integrating the quite abundant archeological data (ca. 100 and 50 occurrences known for Member F and the lower part of Member G, respectively) together with paleoenvironmental data (including several thousands of paleontological specimens from members E and F as well as geological data). Following the level of spatiotemporal accuracy for these different datasets, three analytical scales were used (archeological complex, area of study, whole formation). The spatial and taphonomical analysis of the archeological data combined with the analysis of faunal assemblages allowed demonstrating that only a small number of occurrences record initial settlements in the Member F. They are found in the lower section of Member F, near the Omo paleoRiver, in a general context of landscape opening and increased aridity. In addition, a differential spatial analysis of some taxa between the northern part and the southern part of the Type area suggests a greater prevalence of wet areas in the southern part of the Shungura landscape.

Tiphaine MAURIN a soutenu sa thèse en décembre 2017 dans le cadre de l’Omo Group Research Expedition, programme de recherche transdisciplinaire qui étudie l’impact des facteurs environnementaux sur l’évolution humaine à l’échelle d’une vallée du rift africain.

Plio-Pleistocene hominin dietary ecology

Speaker: Michael BERTHAUME, Imperial College of LONDON

Date: March 30th 2018 – 10:30 am
Location: Room 410 , bat. B35 (3rd floor, North wing), University of Poitiers

Summary: A radiation of Pliocene hominins gave rise to high taxonomic diversity in the Plio-Pleistocene: this is commonly associated with environmental change and dietary shifts. Broadly speaking, it is hypothesized that as the environment became increasingly arid, the australopithecines became more robust by shifting towards more mechanically challenging foods, while early Homo became more gracile by shifting towards less mechanically challenging foods through a dietary shift and/or the introduction of cooking and/or tenderization. To test these hypotheses, a myriad of methodologies have been developed, mostly revolving around postcanine dental remains. As different aspects of diet are reconstructed with different approaches (i.e., dental microwear informs on particles present in/on foods shortly before death, carbon isotopes inform on foods consumed during development, and tooth form and function inform on what selection has acted on previously in that taxon), researchers can only gain a comprehensive understanding of hominin dietary ecology by combining results from all methods. Here I review the dental microwear, carbon isotope, and dental form and function work done on the PlioPleistocene hominins, and discuss how they form a comprehensive story of the dietary ecology of our hominin ancestors. I synthesize this information with evolutionary theory to discuss how dietary niche partitioning in the ancestors of the robust australopithecines and early Homo may have produced selective pressures that led to the evolution of these taxa.

Michael BERTHAUME’s research focuses on the application of the finite element (FE) method to biological systems, focusing on teeth, skulls, and long bones. He is also interested in the overlap between engineering and (paleo)anthropology, dental topography, and eco/functional morphology.

Evolutionary, biological and ecological interests of studying convergent ontogenetic dental traits in mammals

Speaker: Helder GOMES RODRIGUES, Institute of Evolution Sciences of Montpellier (ISEM), CNRS & University of Montpellier

Date: March 19th 2018 – 11:00 am
Location: Room 410 , bat. B35 (3rd floor, North wing), University of Poitiers

Summary: During their evolutionary history, mammals underwent numerous events of diversification that resulted in a large variety of shapes and spectacular examples of morphological convergences. Dental ontogenetic parameters, such as growth, mode of replacement, or the relative timing of dental eruption, were shown to provide clues to better understand the evolution, biology and ecology of extinct and extant mammals. The study of dental convergences thus appears fundamental to understand the evolutionary mechanisms driving the diversification of mammals, as well as their putative adaptations. Here, I will focus on a striking example, the notoungulates, which permits to illustrate the interest of studying morphological convergences in a highly diversified group. Notoungulates are an extinct clade of endemic South American mammals, which present a large diversity of cranial and dental shapes. They also show numerous convergences with extant groups of mammals, such as rhinos, horses, and even rabbits and rodents. I aimed at exploring more accurately the diversity of the masticatory apparatus in notoungulates for a better comprehension of its origin. I will present you the results of a study integrating analyses of dental growth and replacement, and quantification of skull shape using 3D geometric morphometric analyses. These data will be discussed in relation to the main environmental and climatic changes impacting South America from the Late Paleocene onwards.

Helder Gomes-Rodrigues is a specialist of mammalian dental evolution combining evo-devo and paleontological approaches. His work enlightens mechanisms of dental adaptations at macroevolutionary level.

Dysodiles: a papyraceous archive for the lower Barremian of Lebannon

Speaker: Layla EL HAJJ, Institute of Earth Sciences of Paris

Date: March 14th 2018 – 1:15 pm
Location: Room 410 , bat. B35 (3rd floor, North wing), University of Poitiers

Summary: Dysodiles are characterized by their fine millimetric laminations, organic content and richness in fossils. In Lebanon, these rocks croup out in different geological formations. However, despite their paleontological interest they were understudied possibly due to the diverse and extensively studied Lebanese Upper Cretaceous marine series. They were scarcely evoked in the literature of the 19th century with the mention of their presence in the Neocomian sandstones, in which Janensch described two fish species, while Fraas identified some fossil plants. Recently, we re-/discovered numerous outcrops in several Barremian and Albian localities across Lebanon which engage us to study carefully these exceptional series and their poorly-understood depositional context. Our aim is to characterize these environments using sedimentological, paleontological and geochemical tools.
The focus is on the Lower Barremian dysodiles. They belong to the “Grès de base” Formation, represented by up to 300 meters of fluvio-deltaic sandy facies, where 5 outcrops were discovered. The studied deposits correspond to small lakes of limited extension (of a few km2). They are mostly found nearby volcanic altered rocks, or associated to cinerites, suggesting a possible relation between the volcanism and their deposition and/or preservation. We present the first results of our investigations.

Layla El Hajj is a second year PhD student between the Lebanese University and the Sorbonne University. Her work considers the multidisciplinary characterization of the Lebanese dysodiles. In this project, she focuses on the sedimentology, paleontology and geochemistry in order to reconstruct the depositional environment of the dysodiles from the Lower Barremian of Lebanon.

Diversification in Darwin’s dreamponds: a comparative perspective on organismal evolution in the African Great Lakes

Speaker: Bert VAN BOCXLAER, CNRS, Univ. Lille, UMR 8198 Evolution-Ecology-Paleontology, 59000 Lille, France

Date: February 8th 2018 – 10:30 am
Location: Wegener room 105, build. B35 (ground floor, North wing), University of Poitiers

Summary: The East African Great Lakes (EAGL) are collectively the earth’s most remarkable and species-rich freshwater feature. Intrinsic biological factors and extrinsic ecological opportunities allowed much of the lakes’ spectacular biodiversity to evolve through evolutionary (often adaptive) radiation and explosive speciation. The clearest testimony of this evolutionary success in terms of morphological and behavioral disparity as well as species richness is presented by cichlid fishes. However, various aquatic invertebrates likewise diversified markedly in the EAGL and here I highlight aspects of this invertebrate biodiversity, notably of mollusks. Considerable extant diversity and rich archives of wellpreserved, identifiable fossils present an exceptional opportunity to study the evolutionary patterns and processes that have contributed to invertebrate evolution in the EAGL. I exemplify these opportunities with studies on gastropods from Lake Malawi. Integrating paleontological and evolutionary ecological perspectives I focus on the role of neutral and selective processes in evolutionary radiations and how the effects of these processes interact in space. To study how these processes interact in time I examine evolutionary stasis in a fossil gastropod lineage. These studies reveal that rapid changes in morphology over historical periods can be reconciled with limited accumulated change over long (paleontological) timescales. Beyond detailed studies in single lake basins the EAGL presents a ‘natural laboratory of quasi-replicate systems’ on a continental scale, and, hence, the opportunity for comparative studies (focusing on various lake basins and/or several taxa) of organismal evolution. I present insights into continent-wide patterns of diversity, but generalizations are difficult to draw from the taxonomically restricted set of current examples. Nevertheless, insights into evolutionary patterns over various spatial scales (from that of a basin to that of the continent) provide a promising basis to synthesize micro and macroevolutionary perspectives on organismal evolution in the EAGL.

Bert Van Boxclaer is an integrative evolutionary biologist broadly interested in patterns and processes of organismal diversification. He is also a research associate at Ghent University (Belgium) and at the Smithsonian National Museum of Natural History (DC, USA).

Reconstructing terrestrial ecosystems with carbon isotopes and molecular distributions of plant wax biomarkers

Speaker: Kevin UNO, Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, 10025, USA

Date: January 17th 2018 – 10:30 am
Location: Wegener room 105, build. B35 (ground floor, North wing), University of Poitiers

Summary: Exploring the vegetative structure of ancient terrestrial ecosystems has a wide range of applications in the earth sciences that include deep time perspectives on climate change, carbon cycle dynamics, rainfall, and the relationships between climate, plants and faunal evolution. Here, I will demonstrate the utility of plant wax carbon isotopes and molecular distributions, specifically n-alkyl lipids, in reconstructing vegetation from the Neogene to present. In the first part of my talk, I will use examples from terrestrial and marine sedimentary archives to illustrate how compound specific carbon isotope measurements record the timing and nature of the spread of C4 grasses during the late Miocene. These cases, drawn from studies in tropical and subtropical regions around the world, highlight the importance of considering spatial scales when designing biomarker studies. In the second part, I will describe the uses of n-alkane molecular distributions to estimate the fraction of woody cover in past environments. The primary application of this method is to reconstruct vegetation during time periods that predate the late Miocene spread of C4 grasslands, where carbon isotopes cannot differentiate C3 grasses from C3 woody vegetation. Using a data set of modern soils from a range of African ecosystems, I will show that the molecular distributions of odd-numbered, long chain n-alkanes (e.g, C29 to C35) can be used to predict the fraction of woody cover in modern ecosystems.

Kevin Uno is internationally renowned through his contributions using biogeochemistry and aiming at reconstructing past and extant terrestrial ecosystems. He is involved in numerous research projects notably in Africa and Arabia. He has collaborated with PALEVOPRIM since 2013.

GESTIONNAIRES

Laure PAINAULT
laure.painault@univ-poitiers.fr
Tél. : +33 (0)5 49 45 37 53

Guylaine REYNAUD
guylaine.reynaud@univ-poitiers.fr

Tél. : +33 (0)5 49 45 37 26

Fax : +33.(0)5 49 45 40 17

ADRESSE POSTALE

Université de Poitiers – UFR SFA

PALEVOPRIM UMR CNRS 7262

Bât B35 – TSA 51106

6 rue Michel Brunet

86073 POITIERS Cedex 9