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High diversity of Raoellidae (Artiodactyla, Mammalia) from the middle Eocene Subathu Group of Kalakot, Northwest Himalaya, India
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The middle Eocene Subathu Group of Kalakot area (northwest Himalaya, India) is well known for its diverse mammalian fauna, especially of raoellid artiodactyls, which are presently represented by four genera: Indohyus, Khirtharia, Kunmunella, and Metkatius. Our recent work on artiodactyls from the Kalakot area recovered several new taxa in addition to earlier known raoellids. The first new taxon is characterized by its small size, higher and more conical lower molar cusps than in Khirtharia and Metkatius; protoconid and metaconid closely appressed; crista obliqua meets at trigonid notch, presence of an hypolophid and a welldeveloped labial cingulid; bunodont upper molars, subrectangular M1-M2, and subtriangular M3, large metaconule (pseudohypocone) and small well distinct paraconule; cristae well distinct, small metastyle on M3 (absent in the four other raoellid genera), slightly inflated anterior and posterior cingulae. The second new taxon is the smallest of all known Raoellidae; it has bunodont lower molars with tiny paraconid in m1-2 (paraconid is absent in all other raoellids) and crista obliqua meeting the labial base of protoconid; m3 with an hypolophid and well-individualized hypoconulid centrally placed and higher than entoconid; M2 subrectangular, protocone higher than metacone, para and metastyle less distinct than in Indohyus and Kunmunella, ectoloph distinct. Besides these two new taxa, Khirtharia dayi known from Pakistan is reported for the first time from India on the basis of its morphology and size of m3. A new species of Metkatius is characterized on the basis of m1-2, which differ from those of M. kashmirensis by the metaconid higher than the protoconid and by being more than 20% larger. Outside the Indian sub-continent, raoellid artiodactyls are also known from the middle Eocene Pondaung Formation of Myanmar and Shanghuang fissure filling of Jiangsu, China. The predominance of the family Raoellidae in Kalakot provides new information about their phylogenetic position and allow to discuss their origin, evolution, and dispersals. This work is partly funded by project BR/121/A3/PALEURAFRICA from the Belgian Science Policy Office.
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RBINS Staff Publications 2019
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Application of long-term chemostratigraphy (organic carbon isotopes) in age calibration of Paleogene mammal faunas
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Rapid, ‘short-term’ (10 kyr to several 102 kyr) δ13C - δ18O excursions on various materials (bulk, pedogenetic nodules, specific foraminiferal taxa, secondary layer of brachiopods, dispersed organic matter, wood fragments) have been used for decades as reliable stratigraphic tools during the Paleogene (Late Danian Event, PETM or ETM-1, ETM-2, ETM-3, MECO, Oi-1, …). ‘Long-term’ δ13C isotope trends (102 kyr to several myr) may also provide new stratigraphic insights, particularly in sections without any detailed stratigraphic information. Here we show and discuss the potential uses, biases, limits, and perspectives of long-term δ13C isotope trends on organics, from vertebrate-bearing sections in Morocco, Southern France (Corbières, Minervois, Montpellier area, Provence), Angola and Belgium. Using long-term carbon isotopes on organic matter, terrestrial sections can be correlated with the marine stratigraphic international record. Inter- and intraregional correlations are proposed on the basis of bio- and chemostratigraphic calibration of the various records, particularly with the well-known and continuous sections of the Bighorn Basin, Wyoming (USA). These correlations may contribute to the age calibration of the Paleogene mammal faunas (including endemic faunas) and may shed new light on their evolution in different parts of the world. This work was partly funded by the Belgian Science Policy Office, project BR/121/A3/PALEURAFRICA.
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RBINS Staff Publications 2019
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Additional vertebral material of Thaumastophis from the early Eocene of India provides new insights on the early diversification of colubroidean snakes
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The Ypresian Cambay Shale Formation at Vastan, Mangrol, and Tadkeshwar lignite mines in Gujarat, western India, has yielded a rich vertebrate fauna including madtsoid, palaeophiid, booid, and colubroid-like snakes. The latter are particularly abundant but their systematic affinities are difficult to resolve. Here we describe new specimens of the colubroidean-like snake Thaumastophis missiaeni, including anterior, mid-, and posterior trunk vertebrae, as well as caudal vertebrae. This species presents several characters shared with Renenutet enmerwer from the late Eocene of Egypt, suggesting exchange with North Africa probably along the southern margin of the Neotethys. Among these are the presence of parazygosphenal foramina (although not in all vertebrae), deep blade-like prezygapophyseal processes, and thick and tall neural spine. The available vertebral evidence is hardly sufficient to distinguish both taxa from each other, suggesting that these might be even congeneric taxa. However, more material is needed to test more appropriately this hypothesis. Both taxa are considered to be close to the root of the Colubroidean tree. We also revise the Eocene colubroidean fossil record in light of these new findings. This research was funded by grants from National Geographic Society, Leakey Foundation, U.S. NSF, Government of India, Wadia Institute of Himalayan Geology, Belgian Science Policy Office, and Brazilian FAPESP.
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RBINS Staff Publications 2019
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The large trionychid turtles from the early Eocene record of Belgium
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Remains of trionychid turtles are abundant in the early Eocene fossil record of Belgium where several species are recognized. In this context, the remains of several large-bodied individuals, with a shell length of about one meter, stand out both for their size and good preservation. The Royal Belgian Institute of Natural Sciences houses several unpublished large-size specimens, but also others with a high historical value (e.g., those from Erquelinnes and Leval), which had not been, until now, studied in detail. Recent studies proposed that all large trionychids from the Eocene of Western Europe could belong to a single species, attributable to the North American genus Axestemys. However, a valid diagnosis for this putative European single species is not currently available, since the characters that allow its differentiation with each of the North American species have not been well established. Several of the best preserved Belgian specimens have been recently restored, which allows us to perform their detailed study. Thus, the description of several anatomical elements hitherto poorly known or not described for the large-bodied trionychids of the Eocene of Europe can be performed for the first time. The study of the Belgian specimens, which correspond to the most complete and best preserved in Europe, allows us to evaluate the hypothesis on whether they belong to the same species as the other largebodied trionychids found in the Paleogene record of this continent. Thus, this study significantly increases the information on the relatively poorly known Paleogene large trionychids of Europe. This research was supported by network project BR/121/A3/PALEURAFRICA from the Belgian Science Policy Office, and by the Ministerio de Ciencia, Innovación y Universidades (IJCI-2016-30427).
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RBINS Staff Publications 2019
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A DNA-based pipeline for species-level identification of Belgian mosquitoes
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RBINS Staff Publications 2021
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COI haplotypediversity in three exotic Aedes species in Belgium
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RBINS Staff Publications 2021
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Deposits from the 2004 Indian Ocean Tsunami in three coastal ponds in Khao Lak, Thailand
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RBINS Staff Publications 2017
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Towards answering the “so what” question in marine renewables environmental impact assessment
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RBINS Staff Publications 2017
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Lessons learned from the Belgian offshore wind farm monitoring programme, with specific attention to answering the “so what” question
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RBINS Staff Publications 2017
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A peculiar fish jaw with molariform teeth from the early Eocene of Tadkeshwar Mine, India highlights diversity and evolution of early gymnodont tetraodontiforms
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Excavations during 2015 at a channel deposit in the early Eocene Cambay Shale Formation of the Tadkeshwar open cast lignite mine near Vastan in Gujarat Province, western India, have yielded terrestrial mammals, lizards, snakes, frogs, and birds as well as a few marine/brackish-water animals, predominantly teeth of the shark Physogaleus and Myliobatis rays. Among these is a jaw of an unusual teleost. This lower jaw of a gymnodont has fused dentaries, lacks a beak, and shows a remarkable series of teeth that are unique among all known fossil and living Tetraodontiformes. The teeth are molariform with raised “spokes” radiating inward from the emarginated peripheral edge of the crown. Tooth development is intraosseous, with new teeth developing in spongy bone before they erupt and attach to the dentary by pedicels. Although many of the 110 tooth loci in the fossil specimen have lost their teeth, in life the teeth would have grown to fit tightly together to form a broad and continuous crushing surface. The estimated age of the early Eocene Cambay Shale vertebrate fauna is ca. 54.5 Ma, making the jaw the second oldest confirmed gymnodont fossil. Comparisons to extant taxa of gymnodonts with fused dentaries (e.g., Diodon, Chilomycterus, and Mola) offer few clues about evolutionary relationships of the new fossil. Although the fused dentaries suggest affinities to diodontids and molids among living tetraodontiforms, it remains challenging to interpret phylogenetic relationships of the new Indian gymnodont because no living or fossil tetraodontoid has similar tooth morphology. We describe it as a new genus and species, and place it in its own new family of Gymnodontes. Grant Information: National Geographic Society, Leakey Foundation, Belgian Science Policy Office, Tontogany Creek Fund, National Science Foundation, Wadia Institute of Himalayan Geology.
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RBINS Staff Publications 2017
