New basal ruminants from the Eocene of the Pondaung Formation, Myanmar

Two new genera and species of small basal ruminants are described from the middle Eocene Pondaung Formation in Myanmar. One form, Paukkaungmeryx minutus, gen. et sp. nov., is attributed to a primitive Archaeomerycidae, and the other, Stenomeryx bahinensis, gen. et sp. nov., very likely represents the oldest known Tragulidae, a family unknown in Pondaung so far. The fossil record of primitive ruminants in Pondaung is now represented by five genera, and the occurrence of both of these taxa in the Paleogene of Myanmar supports the hypothesis that the initial radiation and diversification of basal ruminants probably occurred during the first part of the Eocene in southern Asia. These discoveries also demonstrate that the fossiliferous sediments of the Pondaung Formation continue to yield new vertebrate taxa that help documenting the evolutionary history of several groups of small mammals.