Presence of the Asian horse Sinohippus in the Miocene of Europe

The Anchitheriinae are a group of browsing horses with a widespread distribution throughout the Miocene. The subfamily includes the genera Hypohippus, Megahippus, Kalobatippus, Anchitherium, and Sinohippus. In the present paper we compare the remains of a giant anchitherine from the Spanish site of Nombrevilla−1, “Anchitherium” sampelayoi, with other species of Anchitherium from Europe, the North American genera Megahippus and Hypohippus, and the Asian genus Sinohippus. These comparisons allow us to suggest the inclusion of this large Spanish browsing horse in the Asian genus Sinohippus, rather than in Anchitherium. This proposal is made on the basis of some morphological traits from the upper cheek teeth of the Nombrevilla−1 fossils, and their large size, which clearly is outside the range of all other known European Anchitherium.