Early Pliocene ochotonids (Mammalia, Lagomorpha) from Southern Ukraine

The aim of this paper is to enlarge knowledge about poorly known ochotonids from the Early Pliocene (Ruscinian, MN 14) from southern Ukraine. The abundant new material of Ochotona antiqua Argyropulo & Pidoplichko, 1939 from Novopetrovka (type locality) and Frunzovka-1 is analyzed in detail and compared with the type material. The results are expressed in a redescription of the taxon and evaluation of its intraspecific variation, including the outlying and/or aberrant forms closely related to it. Pseudobellatona relicta Topachevsky, Nesin & Topachevsky, 1993 confined to the type locality Krasnopol is redescribed and considered herein as a taxon incertae sedis within the Ochotonidae clade. Specificities of the Early Pliocene taxa from the Kuchurganian sedimentary series are discussed in the context of phylogeny and systematics of Eurasian ochotonids.