Although a famous species, H. crassum is actually poorly known : there are no complete skulls, only scanty limb bones and a few teeth that may, or may not, belong to a single species.
A cranium of H. crassum mentioned by Depéret (1890) and chosen as lectotype by Forsten (1968) was never (...)
According to Depéret (1890), H. crassum is found mostly in the Middle Piocene of Roussillon (MN 15), probably also in the Pliocene of Montpellier (MN 14), and possibly in the Red Crags of Suffolk, England, and in the Messinian of Toscany at Casino, Italy. Pirlot (1956) gave figures of some (...)
Hipparion crassum was recognized as a new species by Gervais (1859, 1869) because of its massive limb bones and the rounded protocone of its upper cheek teeeth.
Depéret (1890) gave a more detailed description insisting on the functional reduction of the lateral metapodials, the relatively big (...)