Suoidea from the lower Miocene of Cetina de Aragón (Spain).

Abstract

The Suoidea (Mammalia) of the Lower Miocene (Agenian, MN 2a) locality Cetina de Aragón (Spain) are Hyotherium meisneri, Hyotherium major (Suidae) and Propalaeochoerus sp. A (Tayassuidae). Most of the fossils belong to Hyotherium meisneri; all permanent teeth are represented. Up to now this species was known by few material. Currently, H. meisneri and H. major were considered to be either regional subspecies or synonyms. H. meisneri from Cetina is compared to H. major from its type locality St.-Gérand-le-Puy. The morphology does not differ much, but there is an average size difference of 15 %. Size differences of 15 % are common in sympatric species of suoids and tragulids. As the ranges of H. major and H. meisneri overlap in time and space the two taxa are different species, in stead of subspecies. Hyotherium meisneri is one of the oldest known suids, but shows already the outward fiare in the upper canines of the males, which is typical for the Suidae. Within the Hyotheriinae the genus Hyotherium is characterized by elongated premolars. Propalaeochoerus sp. A from Cetina and Montaigu is similar in size to Propalaeochoerus sp. B from Tomerdingen, but differs in having larger posterior molars and smaller premolars, it might be a direct descendant. These tayassuids and Propalaeochoeruss elaverensis differ from all other Palaeochoerus-like tayassuids, including Palaeochoerus? pusillus, in the elongated last upper molar.