New remains of Siamotherium pondaungensis (Cetartiodactyla, Hippopotamoidea) from the Eocene of Pondaung, Myanmar: Paleoecologic and phylogenetic implications

We describe an exceptionally well preserved skull of a small anthracothere from the late middle Eocene of the Pondaung Formation that can be confidently attributed to Siamotherium pondaungensis, a species that was first diagnosed on the basis of a fragmentary maxilla preserving two upper molars. The new material confirms that Siamotherium pondaungensis is an anthracothere and not a helohyid as repeatedly suggested. According to its dentition and skull structure, Siamotherium pondaungensis was most likely a terrestrial, open-forest animal with an omnivorous diet that showed no significant adaptation to folivory. A phylogenetic analysis that includes both species of Siamotherium confirms their basal position within the Hippopotamoidea. SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP Citation for this article: Soe, Aung Naing, O. Chavasseau, Y. Chaimanee, Chit Sein, J.-J. Jaeger, X. Valentin, and S. Ducrocq. 2017. New remains of Siamotherium pondaungensis (Cetartiodactyla, Hippopotamoidea) from the Eocene of Pondaung, Myanmar: Paleoecologic and phylogenetic implications. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2017.1270290.