Tarsal morphology of the pleuraspidotheriid mammal Hilalia from the middle Eocene of Turkey

Pleuraspidotheriids are a group of primitive ungulate mammals that, until recently, were thought to be restricted to the late Paleocene of Western Europe. It has been hypothesized that this family actually survived in Central Anatolia until at least the middle Eocene. However, these anachronistically young Anatolian “survivors”, including the genus Hilalia, were previously documented mainly by dental remains. Here, we describe the previously unknown astragalus of Hilalia saribeya, which confirms the pleuraspidotheriid affinities of the genus, and supports phylogenetic reconstructions that place Hilalia as the sister group of Pleuraspidotherium. The morphology of the astragalus suggests sub-cursorial plantigrade locomotion for H. saribeya, although its tarsal morphology remains generalized enough that scansorial capabilities cannot be ruled out. The evolution of Hilalia is addressed in the context of the apparent geographic isolation of Central Anatolia during the Eocene. The endemic character of the mammalian fauna of Central Anatolia during the middle Eocene emphasizes how the complex paleogeography of the northern margin of Neotethys impacted local biotas in a region situated at the crossroads of very distinctive biogeographic zones

Tarsal morphology of the pleuraspidotheriid mammal Hilalia from the middle Eocene of Turkey

Pleuraspidotheriids are a group of primitive ungulate mammals that, until recently, were thought to be restricted to the late Paleocene of Western Europe. It has been hypothesized that this family actually survived in Central Anatolia until at least the middle Eocene. However, these anachronistically young Anatolian “survivors”, including the genus Hilalia, were previously documented mainly by dental remains. Here, we describe the previously unknown astragalus of Hilalia saribeya, which confirms the pleuraspidotheriid affinities of the genus, and supports phylogenetic reconstructions that place Hilalia as the sister group of Pleuraspidotherium. The morphology of the astragalus suggests sub-cursorial plantigrade locomotion for H. saribeya, although its tarsal morphology remains generalized enough that scansorial capabilities cannot be ruled out. The evolution of Hilalia is addressed in the context of the apparent geographic isolation of Central Anatolia during the Eocene. The endemic character of the mammalian fauna of Central Anatolia during the middle Eocene emphasizes how the complex paleogeography of the northern margin of Neotethys impacted local biotas in a region situated at the crossroads of very distinctive biogeographic zones

Eocene metatherians from Anatolia illuminate the assembly of an island fauna during Deep Time

Island biotas have disproportionately influenced the history and development of evolutionary biology, but understanding their genesis and evolution across geological timescales has been hindered by a poor fossil record. Here we augment the insular Eocene (~43 Ma) mammalian fauna known from the Pontide terrane of central Anatolia by describing two new metatherian taxa (stem marsupials) from the Lu¨ lu¨k Member of the Uzunc¸arşıdere Formation in the Orhaniye Basin. Geological and paleontological data indicate that the Pontide terrane was an island on the northern margin of Neotethys during the middle Eocene. Reflecting its geodynamic context in a region of active tectonic convergence, the Eocene Pontide terrane hosted a unique combination of Laurasian and Gondwanan mammals, including an anachronistic radiation of pleuraspidotheriids (archaic ungulates) that went extinct on the European mainland ~13 Ma earlier. Most of the mammalian clades occupying the Pontide terrane colonized it by dispersal across marine barriers rather than being stranded there through vicariance. Endemic radiations of pleuraspidotheriid ungulates and polydolopimorphian metatherians on the Pontide terrane reveal that in situ diversification was an important factor contributing to faunal assembly and evolution. The insular fauna that arose on the Pontide terrane is highly analogous to that of modern Sulawesi, which evolved under strikingly similar geological conditions. Illustrating the ephemeral nature of insular biotas across macroevolutionary timescales, the demise of the Pontide fauna coincided with paleogeographic changes enabling more cosmopolitan taxa to reach it for the first time. The high level of endemism shown by the mammalian fauna of the Uzunc¸arşıdere Formation eliminates the Pontide terrane as a potential early Eocene dispersal corridor between western Europe and India.INSU-2011 CT49215-12W296-13EAR- 154368

Oligocene ruminants from the Kizilirmak Formation, Cankiri-Corum Basin, Central Anatolia, Turkey

WOS: 000392102400007A new assemblage of ruminants from five distinct Oligocene localities of the Kizilirmak Formation, Central Anatolia, Turkey is described. The tragulids Iberomeryx parvus, and Iberomeryx sp. (large), as well as a probable large lophiomerycid have been recognized. The stem pecoran Dremotherium guthi, cf. Palaeohypsodontus and a large indeterminate Pecora have been identified as well. In the five localities, the majority of the ruminant material is referred to Iberomeryx parvus, but the sample from the locality Tepe 641 (upper member of the Kizilirmak Formation) shows some distinctive characters suggesting a more derived species/forms that probably lived in more open environments. The ruminant taxa recorded in the Kizilirmak Formation are congruent with a late Oligocene age, probably close in age to the Benara fauna of southern Georgia. The possible occurrence of Palaeohypsodontus in Central Anatolia would significantly expand its geographical range and suggest biogeographical affinities with Central Asia. The ruminant fauna from the Kizilirmak Formation suggests the existence of lowland forests with more open landscapes in central Anatolia during the late Oligocene.TUBITAK, ParisTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK); CNRS, ParisCentre National de la Recherche Scientifique (CNRS); MNHN, Paris; General Directorate of Mineral Research and Exploration (MTA, Ankara)Ministry of Energy & Natural Resources - TurkeyThis work was carried out with the support of several agencies and institutions: the TUBITAK, the CNRS, the MNHN, Paris, and the General Directorate of Mineral Research and Exploration (MTA, Ankara). We thank C. Karaca and C. Ozturk (MTA Museum, Ankara), and all the persons who contributed to the field work. We thank P. Loubry (UMR 7207-CR2P) for the photographs. GM thanks J. van der Made for the good quality photos of the type of I. parvus. We thank the reviewers for their remarks that have improved the manuscript

Paleoenvironment of the Late Oligocene from the Kagizman-Tuzluca Basin (northeastern Anatolia) based on the micro- and macrofloras

The Kagizman-Tuzluca Basin in East Anatolia is still poorly documented for its stratigraphy and in particular its paleofloral assemblages. In this study, the microfloras from the Kagizman-Kotek and Komurlu areas and the macroflora from the Tuzluca area in this basin have been defined to overcome this deficiency. Sedimentary sequences of the Kagizman-Komurlu area have been deposited in terrestrial conditions different from the sequences of the Kagizman-Kotek and Tuzluca areas, which were deposited in brackish conditions near a shallow marine environment. Paleovegetation in eastern Anatolia is represented by mixed mesophytic and coniferous forests restricted to high and middle altitudes (e.g. Pinus, Ulmus, Fagaceae, Engelhardia, Sequoia, Zelkova, Lauraceae, Pterocarya, and Quercus). Open vegetation elements (Asteraceae-Asteroideae, Tubulifloridites spp., Poaceae, and Umbelliferae) in East Anatolia are more predominant than in West Anatolia. The presence of some marine dinoflagellates and Calamus, Lauraceae, and Arecaceae suggests near-seaside plant distribution in the Kagizman-Kotek and Tuzluca areas. According to micro- and macrofloral records and numerical climatic values calculated by the coexistence approach method, paleoclimatic conditions could have changed between warm temperate and subtropical, and also seasonality was effective in East Anatolia during the Late Oligocene. In addition, the paleoclimate of East Anatolia during the Late Oligocene appears to be colder than in West Anatolia based on the palynological data, and this could be related to the high elevation of East Anatolia as compared to West Anatolia. Moreover, the low precipitation values of East Anatolian indicate a dry period in the paleoclimatic conditions of the Late Oligocene

New remains of Lophiaspis maurettei (Mammalia, Perissodactyla) from the early Eocene of France and the implications for the origin of the Lophiodontidae

International audienceThe Lophiodontidae are endemic perissodactyls from Europe that flourished during the Eocene. Despite their preponderance in the European fossil record, their exact origin and relationships within the perissodactyls remain unknown due to the rare and fragmentary material in the early Ypresian, the time of their earliest radiation. Lophiaspis maurettei is the oldest and earliest diverging lophiodontid known to date but is unfortunately poorly known. We describe here the results of new excavations of the type locality of Palette. Important new material including complete skulls, mandibles, post-cranial elements and juvenile specimens lead us to revise Lophiaspis maurettei from Palette and other localities and to describe novel morphology for this species. According to an original phylogenetic analysis, based on a revised matrix of dental, cranio-mandibular and postcranial characters, Ls. maurettei is an early diverging lophiodontid morphologically close to Protomoropus and Paleomoropus, two basal chalicotheres, known from Asia and North America, respectively. Our resulting topology does not support the previously proposed inclusion of the lophiodontids within the Ceratomorpha and supports a position within the suborder Ancylopoda, close to some Eomoropidae representatives. These results imply that Ls. maurettei was restricted to Southern Europe during the early Eocene, which would be compatible with an Asian origin for lophiodontids in accordance with the evolutionary history of other perissodactyls and placental mammal