Work

Dental morphology evolution in early peratheriines, including a new morphologically cryptic species and findings on the largest early Eocene European metatherian

Year: 2024

Type: article

Abstract: The initial stages of the evolutionary history of peratheriines, the European herpetotheriid metatherians, are largely unknown, primarily due to their limited morphological dental disparity throughout the Palaeogene, coupled with significant intraspecific variation. Based on eleven molars, we document a new early peratheriine species, Peratherium musivum sp. nov. which is larger than and morphologically similar to the earliest peratheriine, Peratherium constans (MP7). Subtle molar characters are shared with the largest early Eocene peratheriine, Peratherium maximum comb. nov. We illustrate the importance of studying possible changes in molar cusp – basin proportions and correlated characters that occured during peratheriine evolution. Peratherium musivum sp. nov. which spanned only part of the MP7-MP8 + 9 time interval, and the ~MP8 + 9 Peratherium maximum comb. nov. were probably widespread in Western Europe. The description of a well-preserved mandible of the latter, from La Borie (~MP8 + 9), reveals original features concerning relative size and shape of dental alveoli, partly corroborated using isolated molars. These traits are absent in the younger, most representative species of both peratheriine genera, Peratherium and Amphiperatherium. Based on the aforementioned data and a critical review, it is demonstrated that peratheriine genera lack consistent definitions, so that the Peratherium/Amphiperatherium dichotomy is plausibly inapplicable to early Eocene representatives.This article is registered in ZooBank under urn:lsid:zoobank.org:pub:A2B4DE58-855C-4CB8-BC1D-C9677E6DF97D

Source: Historical Biology

DOI: 10.1080/08912963.2024.2403602

Authors: Killian Gernelle, Marc Godinot, Bernard Marandat, Dominique Téodori, Sandrine Ladevèze, Rodolphe Tabuce