First clear evidence of Anoplotherium (Mammalia, Artiodactyla) in the Iberian Peninsula: an update on the Iberian anoplotheriines.

Abstract

Anoplotheriines (Mammalia, Artiodactyla) were enigmatic, medium- to large-sized ungulates that lived in Western Europe from the late middle Eocene to the earliest Oligocene. The unusual dental and postcranial specializations of these Paleogene mammals have no equivalent in other Cenozoic or contemporaneous artiodactyls on Holarctic landmasses. They appeared abruptly on the Central European Island around the middle to late Eocene transition, but their origin and dispersal through the different areas of the Eocene European archipelago are uncertain. The Iberian fossil record of anoplotheriines is not as well-known as that of other Western European areas. This study examined anoplotheriine artiodactyl fossils from late Eocene (Priabonian) beds at the Zambrana site (Miranda-Treviño Basin, Araba/Álava, Spain). We assign them to at least two different species of anoplotheriines, one in the genus Anoplotherium and the other tentatively assigned to the genus Diplobune. In addition, we described the first cranial and dental elements of Anoplotherium from the Iberian Peninsula. These fossils are crucial for establishing the chronological framework of the Iberian site of Zambrana and understanding the biodiversity and paleobiogeography of the European Eocene artiodactyl fauna.