Lagomorphs (Mammalia) from the early Pliocene of Dorkovo, Bulgaria

The vertebrate locality of Dorkovo yielded a rich mammalian assemblage of which some large mammals have been studied, but not smaller mammals. The previous investigations correlated this fauna to the early Pliocene (early Ruscinian, MN 14). The present paper describes lagomorph remains which consist of one fragment of mandible and 106 isolated teeth. Four species are identified: Ochotona cf. antiqua, Prolagus sorbinii, Alilepus spassovi n. sp. and Trischizolagus crusafonti. The new species is characterised by the derived pattern of its p3 which has trigonid more stretched, enamel infolding stronger than in any other species of Alilepus, and the p3 lacks anteroflexid. The presence of four species of lagomorphs at Dorkovo is in agreement with the diversity dynamics of lagomorphs toward the end of late Miocene and during the early Pliocene in Eurasia, and in particular in Eastern Europe. The time range of the Dorkovo lagomorphs encompasses the Miocene/Pliocene boundary, and this is in agreement with the previous age assignments, i.e., earliest Pliocene, or early part of MN 14 mammalian zone.