Continental vertebrate fauna from the earliest Cretaceous of Angeac-Charente

Article in Geodiversitas with Romain VULLO
2 m-long femur of sauropod dinosaur (turiasaur), unearthed during the 2019 excavation. Copyright Romain Vullo

A monograph (Allain, Vullo, Rozada et al.) describing and analysing the fauna of continental vertebrates from the lowermost Cretaceous of Angeac-Charente (Berriasian, ~140 million years ago) was published on 21 July 2022 in the journal Geodiversitas (Scientific publications of the Muséum national d'Histoire naturelle). Studied since 2010, this major paleontological site has yielded a rich fossil assemblage consisting of more than 50,000 specimens and has the particularity to be composed not only of macroremains, such as dinosaur femurs over 2 metres long, but also of microremains, such as millimetric mammalian teeth. This rich and diverse fauna includes at least 38 different species representing all major groups of vertebrates. Among them, it is worth noting the presence of a new species of ostrich dinosaur (ornithomimosaurus), whose detailed description is under preparation. Described as a bonebed, the Angeac-Charente site is identified as the only continental Lagerstätte ("exceptional fossil-bearing deposit") of earliest Cretaceous age known to date in the world. Many exclusively European genera and species belong to families whose palaeogeographical distribution is essentially Laurasiatic. However, some taxa suggest dispersal events between Africa and Europe during the Jurassic/Cretaceous transition. Such a discovery improves our knowledge about the evolution of continental faunas across the Jurassic-Cretaceous transition. Rather than reflecting an important faunal turnover between the Tithonian and the Berriasian, this fossil assemblage records environmental changes related to the global sea-level regression that characterizes the end of the Jurassic.

Référence : Ronan Allain, Romain Vullo, Lee Rozada, Jérémy Anquetin, Renaud Bourgeais et al.  Vertebrate paleobiodiversity of the Early Cretaceous (Berriasian) Angeac-Charente Lagerstätte (southwestern France): implications for continental faunal turnover at the J/K boundary. Geodiversitas, Museum National d'Histoire Naturelle Paris, 2022, 44 (25), pp.683-752. doi : 10.5252/geodiversitas2022v44a25

Reconstitution de l’ecosystème d’Angeac-Charente il y a environ 140 millions d’années (Crétacé basal). Copyright Mazan.
Reconstruction of the Angeac-Charente ecosystem, 140 million years ago. Copyright :Mazan