ABSTRACT
Seven species of artiodactyls from the Udunga locality in the Selenga basin, Trans-Baikal, Russia, are described: Capreolus constantini, sp. nov., Axis shansius, Orchonoceros gromovi, Alcinae gen. indet., Gazella sinensis, Antilospira zdanskyi, and Ovis sp. Capreolus constantini, the oldest known roe deer, is a possible descendant of Procapreolus wenzensis, which existed at the end of the early Pliocene (zone MN 15). The Udunga fauna is correlated with lower Villafranchian faunas (zone MN 16). The fauna existed on the southern border of the boreal forest at the boundary between the European-Siberian and Central Asian paleozoogeographic sub-areas after 3.5 million years ago.