Stepping into Oligocene. A reassessment of the early Oligocene mammal tracks from Saignon (SE France)

ABSTRACT

The Saignon ichnosite, located in the Apt syncline, yielded a high density of footprints with hundreds of mammal tracks preserved. It was discovered and first studied in the 1970s, and never re-examined since. Here we present a new analysis of the ichnosite with updates to ichnotaxonomy. The surface of the limestone bed bearing the prints was digitised by aerial photogrammetry (UAV). Best preserved tracks and trackways were digitised by short-range photogrammetric techniques. 3D data served as the basis for all measurements, including precise depth measurements. Of the hundreds of tracks present, this study focuses on the 20 best-preserved perissodactyl trackways. A review of the large perissodactyl morphotype is provided and Rhinoceripeda voconcense comb. nov. is defined. We also present possible evidence of social behaviour in early rhinocerotids. Based on fewer tracks a second smaller perissodactyl ichnotaxon, Lophiopus isp. is identified. Artiodactyl prints are attributed, when possible, to Bifidipes velox. The Saignon tracksite, dated as early Rupelian (MP21), is at an important faunal turnover, following the Grande Coupure. Its ichnofauna is characteristic of a post-Grande Coupure fauna with the presence of newcomer rhinocerotids that reached Europe from Asia and the persistence of endemic pre-Grande Coupure palaeotheriids.

KEYWORDS:

• Mammal ichnology
• rhinocerotids
• early Oligocene
• palaeoecology
• ichnotaxonomy

Acknowledgments

We thank M. Gasparik (Hungarian Natural History Museum), L. Makádi (Mining and Geological Survey of Hungary), G. Botfalvai (Eötvös Loránd University) and I. Szarvas (Ipolytarnóc Fossils Nature Conservation Area) for providing access to the type specimen of Rhinoceripeda tasnadyi. We thank Grégoire Métais for thoughtful discussion on Paleogene artiodactyls. We thank the reviewers whose comments strongly improved the manuscript. LP received support from Synthesys+ (access to HU-TAF) and operated under the recognition of the Ministry of Foreign Affairs and International Cooperation (DGDP UFF. VI) for part of this research. We thank Diego Castanera and the reviewers Loïc Costeur and Christian Meyer for their useful comments that helped improving the manuscript. This research was funded by the Geological Nature Reserve of Luberon.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/08912963.2023.2286275.

Additional information

Funding

The work was supported by the Ministero degli Affari Esteri e della Cooperazione Internazionale [DGDP UFF. VI] and by the Geological Nature Reserve of Luberon.