New hippotragini (Bovidae, Mammalia) from the Late Miocene of Toros-Menalla (Chad)

International audienceUntil now, the pre-Pleistocene record of the bovid tribe Hippotragini was rather poor. We describe here two new taxa from the late Miocene of Toros-Menalla in northern Chad, which yielded the earliest known hominid, Sahelanthropus tchadensis. Tchadotragus sudrei n.gen. n.sp. is known by complete skulls and numerous horn-cores. It has typical hippotragine features such as long slender, curved horn-cores, weak cranial flexure, large frontal sinus, and hippotragine-like dentition, and is here taken as a basal member of the tribe, branching before the divergence between Oryx-Praedamalis and Hippotragus s.l. Saheloryx solidus n.gen. n.sp. is less well-known; it differs mainly by the lack of sinus in the frontal and horn-cores, shorter horn-cores, and rounded brain-case, but it shares with Tchadotragus a large number of features that prompt us to classify it also at the base of the hippotragine tree, perhaps as the sister-taxon of Tchadotragus. No other African taxon looks like Saheloryx, and the only one similar to Tchadotragus is from Sahabi, Libya. The abundance of hippotragines sharply distinguishes Toros-Menalla from the East African late Miocene bovid faunas

New Material of the Earliest Hominid from the Upper Miocene of Chad

Anthropolog

Macrovertebrate Paleontology and the Pliocene Habitat of Ardipithecus ramidus

International audienceA diverse assemblage of large mammals is spatially and stratigraphically associated with Ardipithecus ramidus at Aramis. The most common species are tragelaphine antelope and colobine monkeys. Analyses of their postcranial remains situate them in a closed habitat. Assessment of dental mesowear, microwear, and stable isotopes from these and a wider range of abundant associated larger mammals indicates that the local habitat at Aramis was predominantly woodland. The Ar. ramidus enamel isotope values indicate a minimal C4 vegetation component in its diet (plants using the C4 photosynthetic pathway), which is consistent with predominantly forest/woodland feeding. Although the Early Pliocene Afar included a range of environments, and the local environment at Aramis and its vicinity ranged from forests to wooded grasslands, the integration of available physical and biological evidence establishes Ar. ramidus as a denizen of the closed habitats along this continuum

Les grands ongulés du mio-pliocène du Tchad (rhinocerotidae, giraffidae, camelidae) (systématique, implications paléobiogéographiques et paléoenvironnementales)

POITIERS-BU Sciences (861942102) / SudocSudocFranceF

A new Semlikiichthys fish (Teleostei, Perciformes) from the upper Miocene of Chad : fossil record and Palaeobiogeographical implications

International audienc

A new swan (Aves: Anatidae) in Africa, from the latest Miocene of Chad and Libya

International audienc

A window into the early evolutionary history of Cercopithecidae: Late Miocene evidence from Chad, Central Africa

International audienceCentral Africa is known as a major center of diversification for extant Old World Monkeys (OWM) and yet has a poorly documented fossil record of monkeys. Here we report a new colobine monkey (Cercopithecoides bruneti sp. nov.) from the Central African hominin-bearing fossiliferous area of Toros-Menalla, Chad at ca. 7 Ma. In addition to filling a gap in the spatial and temporal record of early OWM evolutionary history, we assess the ecomorphological diversity of early OWM by providing evidence on the onset of a folivorous diet and a partial reacquisition of terrestrial locomotor habits among Miocene colobines. We also support the phylogenetic affinities of the genus Cercopithecoides among the stem group of the extant African colobine monkeys

New Pliocene remains of Camelus grattardi (Mammalia, Camelidae) from the Shungura Formation, Lower Omo Valley, Ethiopia, and the evolution of African camels

International audienceCamels are exceptionally rare in the Plio-Pleistocene fossil record of Africa, hindering attempts to understand the evolution of this family on the continent. Here we describe recently collected camel specimens from the Shungura Formation, Lower Omo Valley, Ethiopia, and attribute these remains to Camelus grattardi. The new specimens date to the late Pliocene (~3 to 2.6 Ma) and consist of three upper molars, one upper premolar, and two proximal metatarsals. The dental specimens confirm this species’ small P4 relative to its molars, a trait that differs significantly from all extant and fossil Old World camels. The metatarsals indicate that C. grattardi was similar in size to the living Bactrian camel, C. bactrianus. Phylogenetically, we find no suitable ancestor, sister, or descendant of the eastern African fossil camel, which suggests greater lineage diversity in Plio-Pleistocene Camelus than previously recognised. Microwear analyses suggest that C. grattardi was likely a mixed-feeder preferring browse, which is consistent with carbon isotopes of enamel from the Turkana Basin. A review of the fossil record of African camels suggests no clear paleoenvironmental association, as fossil camels occur in a range of environments from dry savannas with no permanent water bodies to closed woodlands along the paleo-Omo River