A primitive perissodactyl (Mammalia) from the early Eocene of Le Quesnoy (MP7, France)

Abstract

The Paleocene-Eocene transition is characterised by the first appearance of perissodactyls. Here, we report new fossil data of perissodactyls from the locality of Le Quesnoy (Oise, France, MP7). This locality has yielded one of the oldest and most complete material of perissodactyls from the MP7 reference level of Europe, and it permits description of a new species, Pliolophus quesnoyensis sp. nov. This new taxon is represented by dental and postcranial elements. The large sample from Le Quesnoy allows study of the intraspecific variability in a primitive species of perissodactyl, including sexual dimorphism. The main dental variation concerns the junction between the hypoconulid and the hypolophid on lower molars. These different morphologies of molar crests can vary along the dental row making these characters unreliable for systematic purpose. P. quesnoyensis sp. nov. is closely related to Pliolophus barnesi and Pliolophus vulpiceps known in the MP8–9 beds of the London Clay. It presents some resemblances with North American equids and it possesses more primitive features, suggesting an early dispersal from Europe to North America for equoids. There is no close phylogenetic affinity with the perissodactyls reported from the Eocene of Southern France, thus reinforcing the hypothesis of a substantial provincialism in Europe during the early Eocene. http://zoobank.org/urn:lsid:zoobank.org:pub:E9EF9176-DF9B-4FF3-B78B-9E918D5DBF2B

Keywords:

• Perissodactyla
• Equoidea
• Eocene
• Le Quesnoy
• Europe

Acknowledgements

The convention between the Lafarge-Granulat company, the Langlois-Meurinne family and the MNHN allowed the fieldwork in Le Quesnoy. We would like to thank all the people who participated to the excavations and Eloïse Zoukouba who inventoried a large part of the material. Thanks to Pip Brewer and Jerry Hooker who gave us access to the collection of the Natural History Museum in London. We also thank Lilian Cazes for the photographs, and the fossil preparators of the MNHN for the help with fossil preparation and molding. Finally, we thank the two anonymous reviewers for their insightful remarks that improved the initial version of the manuscript.