The environmental and climatic conditions of the Late Pleistocene of Southern Belgium are here determined for the final part of Marine Isotope Stage 3 (MIS 3) and for MIS 2 on the basis of a study of rodent assemblages. This paper provides a synthesis of several sets of environmental and climatic data from Late Pleistocene sites, all of which are located in southern Belgium. One has previously been published (Caverne Marie-Jeanne), and seven are unpublished (Cavernes de Goyet, Trou des Nutons, Trou du Frontal, Trou de Chaleux, Grotte la Chefalize, Trou du Chˆene, and Trou du Sureau). The habitat weighting and quantified ecology methods are applied to rodent material housed in the Royal Belgian Institute of Natural Sciences (RBINS, Brussels), and previous radiocarbon dates are updated, in order to reconstruct past environments. Among all the sites under analysis, the quantified ecology method shows that Trou de Chaleux corresponds to the coldest temperatures and lowest precipitation. Trou de Chaleux, with a chronology between ca. 15,964–14,014 cal yr B.P., could probably be placed in Greenland Stadial 2 (GS2) or Heinrich Event 1 (HE1). It has a rodent assemblage associated with a predominance of open dry and rocky formations, the most abundant species being the collared lemming and the narrow-headed vole. These data are found to coincide with previous studies carried out on the large-mammal, herpetofaunal, and avifaunal associations of the site, as well as on small-mammal associations from other sites in southern Belgium with similar chronology, such as Grotte Walou. Taken together, this indicates that these latest Pleistocene intervals in southern Belgium were characterized by harsh climatic and environmental conditions. In contrast, the other assemblages under study yielded much more heterogeneous results, frequently inconsistent with an attribution to the Pleistocene. This is likely to be a result of their admixture with Holocene material due to recent intrusions.
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RBINS Staff Publications 2023
Platychelone emarginata Dollo, 1909 is a large turtle from the Late Cretaceous (Maastrichtian) chalk sediments of Limburg, Belgium. Hitherto, only the name was given to this turtle without describing details or providing figures. A single well articulated carapace (IRScNB. Reg. 1681), lacking nuchal, peripherals, and pygal plates, is preserved. The distance from the first costal to the distal end of the eighth costal is 180 cm, indicating that the original carapace was about 210 cm long. Its gigantic size, flattened shell, reduction of distal half of costals, and loss of scute sulcus, indicate that Platychelone is a member of true marine turtles (superfamily Chelonioidea). Neurals are rectangular shape and inclination of the first thoracic vertebra is almost vertical, suggesting this turtle belongs to either Protostegidae or Dermochelyidae. Seventh and eighth costals are medially meeting due to the loss of neurals; this condition is shared with the genus Mesodermochelys from the Late Cretaceous (Santonian to Maastrichtian) of Japan. Thus, it seems most probable that Platychelone is a closest relative of Mesodermochelys among basal dermochelyids. Platychelone has presumed autoapomorphic characters such as very thickened distal ends of thoracic ribs and irregular sculptures on carapace, not seen in any other chelonioids. This genus is only known by the holotype, whereas Allopleuron hoffmanni, a very common cheloniid marine turtle from in the Maastrichtian deposits of Belgium and Netherland, is known from some hundred specimens. So far, there is no ancestral or related taxon of Platychelone from the Campanian deposits of Belgium. The occurrence of Platychelone is very rare but evokes a high taxonomic diversity of gigantic chelonioids in the Cretaceous Tethys.
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RBINS Staff Publications 2017
