212 research outputs found

    : Les Struthionidae et les Pelagornithidae (Aves, Struthioniformes et Odontopterygiformes) du Pliocène final d'Ahl al Oughlam, Maroc

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    International audienceThe Pliocene locality of Ahl al Oughlam is situated at the southeastern limit of the city of Casablanca, in Morocco, on an ancient seashore of the Atlantic Ocean. It has yielded a very rich vertebrate fauna (macro- and micromammals, birds, reptiles, amphibians and fishes) including both terrestrial and marine forms. On the basis of biostratigraphy, the fauna has been dated at about 2.5 Ma, which corresponds to the latest Pliocene. The avifauna is very diverse and includes birds belonging to twelve different orders. In this paper we describe only the Struthionidae and the Pelagornithidae. Ostriches are represented by a large-sized form, referred to the extinct species Struthio asiaticus Milne-Edwards, and its eggshells, of struthioid type, are comparable to those of the recent species Struthio camelus, but thicker. The Pelagornithidae, giant marine birds with bony pseudoteeth, are represented by an extinct species of the genus Pelagornis. As far as we know, this species was probably the latest representative of the order Odontopterygiformes.Le gisement pliocène d'Ahl al Oughlam est situé à la limite sud-est de la ville de Casablanca, au Maroc, sur un ancien rivage de l'Océan Atlantique. Il a livré une très riche faune de Vertébrés (macro- et micromammifères, oiseaux, reptiles, amphibiens et poissons), appartenant surtout à des formes terrestres, mais comportant aussi des formes marines. Des arguments biostratigraphiques ont permis de dater cette faune de 2,5 Ma, ce qui correspond au Pliocène final. L'avifaune est très diversifiée et comporte des oiseaux appartenant à douze ordres différents. Dans cette étude nous décrivons seulement les Struthionidae et les Pelagornithidae. Les autruches sont représentées par une forme de grande taille, attribuée à l'espèce éteinte Struthio asiaticus Milne-Edwards, et leurs coquilles d'œufs, de type struthioïde, sont comparables à celles de l'espèce actuelle Struthio camelus, mais sont plus épaisses. Les Pelagornithidae, oiseaux marins géants à pseudodents, sont représentés par une espèce éteinte du genre Pelagornis. Les restes trouvés à Ahl al Oughlam correspondent probablement aux derniers réprésentants connus de l'ordre des Odontopterygiformes

    Pliocene Rhinocerotidae (Mammalia) from Hadar and Dikika (Lower Awash, Ethiopia), and a revision of the origin of modern african rhinos

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    http://www.vertpaleo.org/jvp/contents-25-2.htmlInternational audienceFossil representatives of the two extant African rhinoceros lineages, Ceratotherium and Diceros, co-occur in the Pliocene deposits of the Hadar Formation, Ethiopia. Both arose, in turn, from Ceratotherium neumayri of the late Miocene. The first of these Pliocene species, Ceratotherium mauritanicum, can be distinguished from the living C. simum, to which it probably gave rise in the earliest Pleistocene, by its less plagiolophodont cheek teeth. The second, Diceros praecox, is closely related to D. bicornis although many specimens, including the type, were previously referred to Ceratotherium. The teeth of D. praecox are little changed relative to those of its Miocene ancestor, but its skull displays the apomorphic rearrangements typical of D. bicornis, suggesting increased browsing specialization. The split between the two lineages probably indicates ecological divergence and character displacement between browsing versus grazing specializations

    A new caprin bovid (Mammalia) from the late Miocene of Morocco

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    We describe here a bovid skull from the Upper Member of the Aït Kandoula Formation near Ouarzazate, Morocco, which can be dated by biostratigraphy to the late Miocene, Turolian-equivalent.We assign it to a new taxon, Skouraia helicoides, gen. nov., sp. nov. It has long horn-cores that are much inclined backwards, strongly spiralled in homonymous direction, very divergent, and have a strong anterolateral keel. The strong cranial flexure, broad basioccipital, and aegodont teeth demand inclusion of this new taxon within the tribe Caprini, a mostly Eurasian group with few African representatives. Skouraia must be an early offshoot of this tribe, but its highly derived cranial features suggest that the Caprini may have experienced, in the poorly known late Miocene of Africa, a broader morphological diversification than in Europe

    Pleistocene hominins as a resource for carnivores. A c. 500,000-year-old human femur bearing tooth-marks in North Africa (Thomas Quarry I, Morocco)

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    In many Middle Pleistocene sites, the co-occurrence of hominins with carnivores, who both contributed to faunal accumulations, suggests competition for resources as well as for living spaces. Despite this, there is very little evidence of direct interaction between them to-date. Recently, a human femoral diaphysis has been recognized in South-West of Casablanca (Morocco), in the locality called Thomas Quarry I. This site is famous for its Middle Pleistocene fossil hominins considered representatives of Homo rhodesiensis. The bone was discovered in Unit 4 of the Grotte à Hominidés (GH), dated to c. 500 ky and was associated with Acheulean artefacts and a rich mammalian fauna. Anatomically, it fits well within the group of known early Middle Pleistocene Homo, but its chief point of interest is that the diaphyseal ends display numerous tooth marks showing that it had been consumed shortly after death by a large carnivore, probably a hyena. This bone represents the first evidence of consumption of human remains by carnivores in the cave. Whether predated or scavenged, this chewed femur indicates that humans were a resource for carnivores, underlining their close relationships during the Middle Pleistocene in Atlantic Morocco

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

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    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

    LES SITES D’INTERETS PRÉHISTORIQUES ET BIO-ECOLOGIQUES DE CASABLANCA. CARACTÉRISATION ET VALORISATION

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    Casablanca,the metropolis and economic center of Morocco, contains in its old quarries a unique archeological and paleontological heritage of great scientific, pedagogic and touristic value. Reflecting a rich past recounting the events preserved in these geological formations as well as the prehistoricalevolutionof the mankind in Casablanca. Other quarries tend to become bio-ecological sites. The inventory of these quarries shows an alarming situation due to anthropogenic threats resulting from human activities such as urban development and pollution. The preservation of this heritage for the future generations is a shared responsibility between authority, citizens, researchers andsocio-economic sector. Their valorization, such as the development of a geotourism circuit will promote even local ecotourism

    Messinian age and savannah environment of the possible hominin Graecopithecus from Europe

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    Dating fossil hominids and reconstructing their environments is critically important for understanding human evolution. Here we date the potentially oldest hominin, Graecopithecus freybergi from Europe and constrain the environmental conditions under which it thrived. For the Graecopithecus-bearing Pikermi Formation of Attica/Greece, a saline aeolian dust deposit of North African (Sahara) provenance, we obtain an age of 7.37-7.11 Ma, which is coeval with a dramatic cooling in the Mediterranean region at the Tortonian-Messinian transition. Palaeobotanic proxies demonstrate C4-grass dominated wooded grassland-to-woodland habitats of a savannah biome for the Pikermi Formation. Faunal turnover at the Tortonian-Messinian transition led to the spread of new mammalian taxa along with Graecopithecus into Europe. The type mandible of G. freybergi from Pyrgos (7.175 Ma) and the single tooth (7.24 Ma) from Azmaka (Bulgaria) represent the first hominids of Messinian age from continental Europe. Our results suggest that major splits in the hominid family occurred outside Africa

    Kantis: A new Australopithecus site on the shoulders of the Rift Valley near Nairobi, Kenya

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    ケニア・ナイロビ郊外で初めて発見されたアウストラロピテクス. 京都大学プレスりリス. 2016-03-24.Most Plio-Pleistocene sites in the Gregory Rift Valley that have yielded abundant fossil hominins lie on the Rift Valley floor. Here we report a new Pliocene site, Kantis, on the shoulder of the Gregory Rift Valley, which extends the geographical range of Australopithecus afarensis to the highlands of Kenya. This species, known from sites in Ethiopia, Tanzania, and possibly Kenya, is believed to be adapted to a wide spectrum of habitats, from open grassland to woodland. The Kantis fauna is generally similar to that reported from other contemporaneous A. afarensis sites on the Rift Valley floor. However, its faunal composition and stable carbon isotopic data from dental enamel suggest a stronger C4 environment than that present at those sites. Although the Gregory Rift Valley has been the focus of paleontologists' attention for many years, surveys of the Rift shoulder may provide new perspective on African Pliocene mammal and hominin evolutio
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