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Neogene (Siwalik-aged) deposits from India and Pakistan have yielded many vertebrate fossils, of which most were named during the 19th century, including numerous geoemydid turtles. In contrast to many other faunal components from the Siwaliks, geoemydids have not undergone taxonomic revision for more than a century and most fossils have therefore been believed to correspond to recent taxa. In this study, we conduct a taxonomic revision of all previously described geoemydid material from the Siwalik-age. We propose that all specimens of 'Clemmys' from the Siwaliks of Punjab, Pakistan should be identified as Melanochelys sivalensis comb. nov.; that Melanochelys tricarinata var. sivalensis represents a valid species, for which we propose the replacement name Melanochelys tapani to avoid homonymy; that specimens originally identified as Batagur cautleyi and Pangshura flaviventer cannot be identified beyond the generic level; and that many fragmentary palatochelydians cannot be identified to any particular species or genus due to the lack of preserved diagnostic osteological characters. With a few exceptions, the Siwalik fauna mostly corresponds in its distribution to that of the recent fauna, indicating a certain amount of geographic stasis. However, as the stratigraphic provenance of most material is poor, it is not possible to discern meaningful temporal patterns.
Fossil dental remains are an archive of unique information for paleobiological studies. Computed microtomography based on X-ray microfocus sources (X-μCT) and Synchrotron Radiation (SR-μCT) allow subtle quantification at the micron and sub-micron scale of the meso- and microstructural signature imprinted in the mineralized tissues, such as enamel and dentine, through high-resolution “virtual histology”. Nonetheless, depending on the degree of alterations undergone during fossilization, X-ray analyses of tooth tissues do not always provide distinct imaging contrasts, thus preventing the extraction of essential morphological and anatomical details. We illustrate here by three examples the successful application of neutron microtomography (n-μCT) in cases where X-rays have previously failed to deliver contrasts between dental tissues of fossilized specimen.
Recent extension works of the quarry of La Gouraudière in Mauzé-Thouarsais (in Deux-Sèvres), and excavation works for the water reservoirs to irrigate the cereal fields in Le Bernard (in Vendée) led to the collection of an interesting fauna of ammonites among which several species are close to the téthysian ones.