Search publications of the members of the Royal Belgian institute of natural Sciences
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The groundwater oligochaetes (Annnelida, Clitellata) from the "Parc du Mercantour" (France)
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New diverse Early Eocene snake assemblage from Tadkeschwar Lignite Mine, Western India
- A diverse snake fauna has been described from the early Eocene Cambay Formation of the Vastan lignite mine, Gujarat, western India, among which early colubroid caenophidians were the most remarkable. Here we describe a new snake assemblage from the approximately contemporary nearby Tadkeshwar mine situated about 10 km southwest of Vastan. As at Vastan, the material from Tadkeshwar is represented only by vertebrae. There are several species in common with Vastan, such as the small madtsoiid gen. et sp. indet. that possesses a haemal keel, the co-occurring palaeophiids Palaeophis sp. and Pterosphenus sp., the same indeterminate boid, and Thaumastophis missiaeni (Caenophidia incertae sedis). However, the most abundant snakes in Tadkeshwar are the madtsoiids. Among them is a new giant madtsoiid that exhibits morphology broadly similar to Gigantophis and Madtsoia. However, it differs in having dorso-ventrally compressed vertebrae with oval cotyles and condyles and a strong notch on the posterior part of the neural arch. The major axis of the prezygapophysis is transverse in dorsal aspect and the parapophysis is very developed and extends beyond the lateral extremity of the prezygapophysis. The haemal keel is absent. While the composition of the Tadkeshwar fauna, like that from Vastan, is reminiscent of the early Eocene of Europe, the large madtsoiid suggests a Gondwanan paleogeographic origin. Indeed, such large madtsoiids are known only from the Late Cretaceous and Paleogene of South America, Africa and the Indian subcontinent, and the late Paleogene and Neogene of Australia. More importantly, the snake assemblage from Tadkeshwar indicates that Laurasian taxa of European affinities were still mixed with relict taxa from Gondwana during the early Eocene before or near the India-Asia collision. Grant Information National Geographic Society, Leakey Foundation, Wadia Institute of Himalayan Geology, Belgian Science Policy Office
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An exceptionally well preserved primate petrosal from the Early Eocene of India
- The Early Eocene (~54.5 Ma) Cambay Shale Formation at Vastan lignite mine (Gujarat, India) has yielded remains of both adapoid and omomyoid primates. The collection of primates includes not only jaws and teeth, but numerous exquisitely preserved postcranial elements. We report on the first cranial specimen for a primate from these deposits: an isolated left petrosal that preserves a partial stapes in anatomical position. The petrosal is identified as a primate based on the remnants of a petrosal bulla, and the presence of an ossified tube for the stapedial artery. The specimen documents a posterolateral entry of the internal carotid artery to the middle ear and a lateral course for the promontorial artery across the promontorium, characters most consistent with an attribution to Adapoidea. Of the adapoids published from the Vastan mine, body mass estimates based on the radii of the semicircular canals, calculated from high resolution microCT data, are most in line with previously calculated estimates for Marcgodinotius indicus, so the specimen is provisionally attributed to that species. Preserved anatomy is largely consistent with that described for Cantius. In particular, although the stapedial artery passed through a bony tube, the promontorial artery ran in an open groove from its origin off the internal carotid artery. This contrasts with the condition in omomyoids and most other adapoids, in which the promontorial artery was carried in a bony tube. The identification of an open groove for this artery in Cantius has been somewhat controversial, based on the state of preservation of published specimens. The petrosal from Vastan is extremely well preserved, demonstrating a clear opening in the internal carotid artery bony tube for the exit of the promontorial artery, and a well-demarcated groove on the promontorium for the latter artery that was clearly not enclosed. The absence of a bony tube for the promontorial artery in the oldest known adapoids suggests that the tube arose independently, in parallel, in Omomyoidea and Adapoidea. The promontorial artery is always enclosed in modern haplorhines, but when this artery is retained in living strepsirrhines it is often not fully enclosed by bone. Therefore, the primitive adapoid condition is more similar to that observed in Strepsirrhini. The antiquity and fine quality of preservation of this specimen make it relevant to reconstructing auditory morphology near the base of the primate tree. Grant Information Supported by an NSERC Discovery Grant to MTS and grants from the National Geographic Society and the Leakey Foundation to KDR.
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New Early Eocene mammal assemblage from Tadkeshwar Lignite Mine, Western India
- The Ypresian Cambay Formation at Vastan and Mangrol mines in Gujarat, western India, has yielded a rich vertebrate fauna with a large proportion of small to middle-sized mammal taxa of European affinities. Here we report a new, approximately contemporary mammal assemblage from the nearby mine of Tadkeshwar. Two fossil layers have been discovered. The older one is a grey clayey sand situated a few meters above the lower major lignite seam and represents a fluvial deposit. The younger layer is a lenticular dark clayey silt, lignitic and rich in organic remains situated just below the upper major lignite seam. This younger layer is sedimentologically similar to the famous fossiliferous lenses known from Vastan. These two fossil layers have yielded a mammal fauna similar to that of Vastan with the co-occurrence of the perissodactyl-like cambaytheriid Cambaytherium thewissi, the adapoid primates Marcgodinotius indicus and Asiadapis cambayensis, and the hyaenodontid Indohyaenodon raoi. The presence of these species in both mines and at different levels suggests that the deposits between the two major lignite seams represent a single mammal age. Apart from the aforementioned classic species there are at least two new species. A new smaller but abundant cambaytheriid is represented by upper and lower jaws, many isolated teeth and postcranial bones. A new esthonychid tillodont is described based on a dentary with m3, an isolated m2, two upper molars and two lower incisors. This new fauna from Tadkeshwar also contains the first large early Eocene vertebrates from India including an unidentified perissodactyl-like ungulate, a mesosuchian dyrosaurid-like crocodiliform and a giant madtsoiid snake. This latter group is particularly diversified in Tadkeshwar. Among the Tadkeshwar vertebrates, several taxa are of Gondwanan affinities attesting that the early Eocene was a crucial period in India during which Laurasian taxa of European affinities coexisted with relict taxa from Gondwana before the India-Asia collision. Grant Information Fieldwork and research supported by National Geographic Society, Leakey Foundation, Wadia Institute of Himalayan Geology, Belgian Science Policy Office.
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Evolution of the European mesonychid mammals and theur bearings on the European Paleoecosystems and biostratigraphy
- European mesonychids are represented by few specimens found only in late Paleocene and early Eocene localities. Recent field works in Palette and La Borie (Ypresian of France) resulted in the discovery of new mesonychid specimens. Additionally, our review of the mesonychids housed by European scientific institutions allowed establishing the occurrence of Dissacus in Berru (Thanetian) and Sézanne-Broyes (Ypresian). Only the genera Pachyaena and Dissacus are recognized in Europe. Furthermore, two new Dissacus species can be defined from the Ypresian localities of Palette, Sézanne-Broyes and La Borie. We also identified from three localities several postcranial elements that could be referred to Dissacus. The preliminary study of this postcranial material suggests a cursorial locomotion. As a result of our study, we propose a scheme of evolution comprising three phases for these particular mammals in Europe. (1) The mesonychid Dissacus dispersed into Europe during Thanetian, probably from North America; it survived the PETM event and even possibly experienced a dwarfism during this global warming. (2) The very large mesonychid Pachyaena migrated into Europe shortly after the Paleocene–Eocene boundary, but it seems that it did not coexist with Dissacus: it was restricted to Northern Europe, while Dissacus was possibly present at that time only in southern areas. (3) However, Pachyaena rapidly disappeared from the European environments, while Dissacus dispersed subsequently into Northern Europe. These data support the existence of a faunal turnover in Northern Europe shortly after the PETM event: it has been notably proposed for explaining the disappearance from Europe of the carnivorous oxyaenids and hyaenodont sinopines, and their subsequent replacement by taxa from the southern areas. The persistence of Dissacus in Europe shows that size was not the main selective factor during this dramatic period. Dissacus has evolved endemically during Thanetian and Ypresian in Europe where it reached a very large size, especially in southern France and Spain. Due to its size, dental, and locomotor adaptations, Dissacus was probably the top mammal predator in Europe. It survived in Europe after its disappearance from North America, possibly due to its ecologic position and the lack of competitors. Grant Information This abstract is a contribution to the project BR/121/A3/PALEURAFRICA funded by the Belgian Science Policy Office.
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Palaeolithic dogs and Pleistocene wolves revisited: a reply to Morey
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L’origine paléolithique du chien
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Molecular Phylogeny of the Extinct Giant Deer, Megaloceros giganteus
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Analysis of postcranial elements of cave bear material (Ursus spelaeus) from Goyet (Condroz/Belgium)
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Influence of climate on sexual segregation and cub mortality in Pleniglacial cave bear
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The Pleniglacial cave bears from Goyet, Belgium
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Systematics and osteometry of Late Glacial foxes from Belgium
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Two cave bear assemblages from Goyet (Chamber A, horizon 1 and 3), Belgium
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Sexual dimorphism and morphometric variability of cheek teeth of the cave bear (Ursus spelaeus)
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Mammoth taphonomy of two fluvial sites from the Flemish Valley, Belgium
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Dinosauriërs: van vindplaats tot museum
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The cave bear (Ursus spelaeus) from Goyet, Belgium. The bear den in Chamber B (bone horizon 4)
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The Magdalenian upper horizon of Goyet and the late Upper Palaeolithic recolonisation of the Belgian Ardennes
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Mammalian remains from the Upper Palaeolithic site of Kamenka, Buryatia (Siberia)
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Pilot study on tree canopy fogging in an ancient oak-beech plot of the Sonian forest (Brussels, Belgium)
