Supplementary material for Roca-Neyra Equids: Late Miocene to Early Pleistocene Hipparion - Equus database for multivariate and statistical analysis for European fossil Equids

We undertake a redescription of the equid sample from the early
Pleistocene of Roca – Neyra, France. This locality has been recently
calibrated at the Pliocene/Pleistocene boundary (2.6 ± 0.2 Ma) and
therefore it is of interest for the first appearance of the genus Equus
and last appearance of hipparionine horses. The Roca – Neyra equid sample,
re – analyzed herein using morphological, morphometrical and statistical
analyses, has revealed the co – occurrence of Plesiohipparion cf. ?P.
rocinantis and Equus cf. E. livenzovensis. The analysis undertaken on
several European, African and Asian “Hipparion” sensu lato species from
late Miocene to early Pleistocene has revealed different remnant Hipparion
lineages in the Plio – Pleistocene of Europe: Plesiohipparion,
Proboscidippaion and likely Cremohipparion. The discovery of the first
European monodactyl horse, Equus cf. E. livenzovensis in itself correlates
Roca – Neyra with other 2.6 Ma European localities in Italy, Spain and in
the Khapry area (Azov Sea region). The morphological description of the
Equus cf. E. livenzovensis lower cheek teeth has highlighted intermediate
features between the North American Pliocene species Equus simplicidens
and early Pleistocene European Equus stenonis. Our study supports the
hypothesis that E. livenzovensis is a plausible evolutionary predecessor
for the Equus stenonis group. These observations underscore the importance
of Roca – Neyra, as an important locality for the last European hipparions
and the first Equus in the early Pleistocene of Europe.