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Inproceedings Reference A tool for feeding and mating: the Swiss Army stylet of Gyratrix hermaphroditus (Rhabdocoela, Platyhelminthes)
Located in Library / RBINS Staff Publications 2023 OA
Inproceedings Reference A new large species of the snake Palaeophis from the Lutetian marine margin of the Congo Basin, Cabinda, Angola
Numerous fossil localities were investigated in western central Africa during the Belgian expeditions that started in the 19th century. At least 47 localities were excavated or analyzed in the framework of Edmond Dartevelle’s paleontological expeditions of 1933 and 1937-1938, producing a large and unique collection of Mesozoic-Cenozoic vetebrates from the margin of the Congo Basin along the coastal area of Angola to Gabon. Among them, snake vertebrae from the marine Paleocene-Eocene Landana section, Cabinda enclave, Angola have been referred to the aquatic snake Palaeophis aff. typhaeus. New investigation of the old Dartevelle’s collections has led to relocation of a few undescribed snake vertebrae from Landana and the nearby locality of Sassa Zao, permitting a revision of Palaeophis aff. typhaeus. The results of this work indicate that all specimens from Landana originate from the same stratigraphic level (layers 31-32) and are of Lutetian age based on the rich associated elasmobranch fauna. The locality of Sassa Zao is also Lutetian based on elasmobranchs that are similar to those of layer 32 of Landana. All of the vertebrae, ten in total, can be attributed to a single large species of Palaeophis. The maximum width across the prezygapophyses is 35 mm and the maximum length of the centrum is 27 mm. The weak lateral compression of trunk vertebrae, low development of the pterapophyses, diapophyses not very low, and the marked lateral projection of the zygapophyses indicate that this species belongs to the ‘primitive’ grade of Palaeophis and thus differs from species of the ‘advanced’ group such as P. casei, P. ferganicus, P. littoralis, P. toliapicus, P. typhaeus, P. grandis, P. tamdy, P. nessovi, and P. udovichenkoi. Among ‘primitive’ grade species, it differs from the giant P. colossaeus by smaller size, proportionally longer vertebrae, the cotyle and condyle more oval in shape, and the zygosphene not larger than the cotyle; from P. africanus by the neural spine that does not approach the zygosphene and shorter hypapophyses that are not prolonged by a ventral carina; from P. vastaniensis, P. virginianus, and P. zhylan by less depressed vertebrae. In size and morphology it most closely resembles P. maghrebianus but differs by more developed hypapophyses and paradiapophyses that do not extend over the cotyle posteriorly. This new species was apparently poorly adapted to aquatic life and was more closely related to the North African Ypresian P. maghrebianus than to West African Lutetian species. Grant Information This abstract is a contribution to the project BR/121/A3/PalEurAfrica funded by the Belgian Science Policy Office.
Located in Library / RBINS Staff Publications 2016
Inproceedings Reference A new hapalodectid (Mesonychia, Mammalia) from the Late Paleocene of the Qianshan Basin (Anhui Province, China): new data on the radiation of the hapalodectids
Mesonychians are an extinct group of primitive hoofed mammals. They have been found all over Laurasia and were well diversified: more than 20 genera are presently recorded. Mesonychia are divided into two families: Hapalodectidae and Mesonychidae. Hapalodectidae are recorded from the late Paleocene to the middle Eocene in Asia (Gashatan to Irdinmanhan), and in the early Eocene in North America (from Wasatchian to early Bridgerian). Hapalodectids remained small: the species of Hapalodectes, the type genus of the family, weighed between 500 g and 1 kg. Because the hapalodectids are relatively rare mammals, the discovery of new specimens, especially in the Paleocene, is crucial for understanding the evolution of these peculiar mammals. Field work in Qianshan Basin (Anhui Province, China) led to the discovery of a new lower jaw of the mesonychian Hapalodectes in Gashatan (late Paleocene) sediments. It is worth noting that the fragmentary mandible is only the third specimen of Hapalodectidae discovered in the Paleocene, and the first in southeast China. The premolars and molars of the new fossil are morphologically similar to Hapalodectes dux, the most primitive hapalodectid, but their relative proportions recall H. paleocenus and the Eocene Hapalodectes species. As a result, the fossil described herein appears to be different from the other previously described species of Hapalodectes in being morphologically intermediate between H. dux and the other Hapalodectes species; it is thus identified as a new species. Its discovery is important because it sheds light on the initial radiation of the hapalodectids. The presence of the most primitive hapalodectids in Mongolia (e.g., H. dux) suggests that the Mongolian area is the center of origination of this carnivorous family. The differences between the new species and the Eocene hapalodectids from China, H. huanghaiensis and H. hetangensis, imply that these species do not derive from the newly described species. Therefore, the new Chinese hapalodectid allows reconstructing the existence of two dispersals from the Mongolian area to the southeast of China, before and shortly after the Paleocene–Eocene boundary. At that latter time, Hapalodectes also dispersed from Asia to North America; this event was part of the 'East of Eden' dispersals. The Paleocene/Eocene transition thus appears as a crucial event for the distribution and radiation of the hapalodectids with the establishment of two distinct groups, respectively in North America and in the southeast of China. Grant Information This abstract is a contribution to the Belgian Bilateral Cooperation Project Belspo BL/36/C54 and China International S&T Cooperation Project MOST 2009DFA32210.
Located in Library / RBINS Staff Publications 2016
Inproceedings Reference Radiation of plesiadapid mammals at the end of the Paleocene evidenced by new discoveries from the Latest Paleocene of France: one more example of bush-like evolution
Plesiadapidae are usually considered to be the closest relatives to the crown-group primates, despite their disappearance at the Paleocene–Eocene Boundary (PEB) in North America, right when the first euprimates appear. In Europe, however, the family survives a few million years after the PEB, though only represented by the genus Platychoerops. Because Plesiadapis was restricted to the Paleocene and Platychoerops restricted to the Eocene, a linear evolution was implied: the genus Plesiadapis was thought to give rise to Platychoerops at the PEB due to the particular environmental conditions of that time. However, one species of Platychoerops was recently described from the late Paleocene of Berru, France, casting doubts on this hypothesis. The recently discovered locality of Petit-Pâtis (Rivecourt, Oise, France) delivered for the first time the most diagnostic tooth of Platychoerops in the Paleocene, its long and derived I1. This discovery confirms the presence of the genus Platychoerops in the Paleocene and attests a quick diversification, bush-like radiation of the family into three genera, before the PEB. The locality of Petit-Pâtis also delivered specimens referable to a new species morphologically intermediate between Plesiadapis tricuspidens and Platychoerops antiquus, with a critical I1 very similar to P. tricuspidens but closer to P. antiquus by its more molarized and proportionally larger p4; this latter derived character is shared with Platychoerops, so that the hypothesis of the North American species P. cookei being the most derived species of Plesiadapis and having given rise to Platychoerops can now be questioned, and a more geographically parsimonious hypothesis of a European origin of the European genus Platychoerops is supported. Finally, the third European genus of Plesiadapidae, Chiromyoides, is also present in Petit-Pâtis, where it is represented by a new species characterized by a smaller size than C. campanicus and the presence of relatively large accessory cuspules aside the posterocone on I1. The specimens from Petit-Pâtis also confirm the hypothesis that Platychoerops georgei from the earliest Eocene is likely a composite species based on the assemblage of a few specimens from different localities of similar estimated age, most specimens likely belonging to Plesiadapis or Platychoerops, while the holotype (a short I1) belongs either to Chiromyoides or to Plesiadapis, its preservation state making the identification difficult. Grant Information This abstract is a contribution to the project BR/121/A3/PalEurAfrica funded by the Belgian Science Policy Office.
Located in Library / RBINS Staff Publications 2016
Unpublished Reference Methane Dynamics in the Belgian Coastal Zone
Very high CH4 concentrations (up to 1,100 nmol L-1) were observed in surface waters of the BCZ compared to open oceanic conditions (<5 nmol L-1) due to release of CH4 from sediments (in-situ production and leakage from gassy sediments) and the well-mixed water column that allows an efficient transfer of CH4 from bottom waters to surface waters. Our data suggest that further warming of surface waters could increase CH4 emissions and provide a positive feedback on warming climate. This feedback will be expected to be acute in shallow gassy areas such as the BCZ since they are natural hotspots of CH4 emission, and the well-mixed water column will allow an efficient propagation of additional heat to the sediment that will be buffered by seasonal thermal stratification in deeper seep areas. The increase of temperature will stimulate the biogenic CH4 production, as well as, decrease Henry’s constant promoting bubbling from sediments. Poster presentation at North Sea Conference 2016, Oostende.
Located in Library / RBINS Staff Publications 2016
Inproceedings Reference Angiostrongylus chabaudi natural infection in wild caufght gastropods
Located in Library / RBINS Staff Publications 2023 OA
Inproceedings Reference A Barcoding Facility for Organisms and Tissues of Policy Concern
Located in Library / RBINS Staff Publications 2022 OA
Located in Library / RBINS Staff Publications 2019
Located in Library / RBINS Staff Publications 2019
Located in Library / RBINS Staff Publications 2019