Review on the taxonomic status of Hexaprotodon iravaticus (Mammalia, Artiodactyla, Hippopotamidae) from the Neogene of Myanmar

The taxonomic status of the primitive hippopotamuses, Hexaprotodon iravaticus, is reevaluated. This species is interested for its smaller size and narrow symphysis which are the characters of the primitive Hexaprotodon species. Because of the lectotype is not an adult specimen and poorly known on its recovered horizon and age, Hex. iravaticus has been rejected from the phylogenetic analyses and discussion of Asian Hippopotamidae. Recently, well preserved dental and partial skull materials of fossil hippopotamuses are newly discovered from the Neogene sediments of Myanmar. That discovery prompted to reclassify the fossil hippopotamuses of Asia, resulting the adult specimens has also shown distinguishable taxonomic characters and the Pliocene discovery for Hex. iravaticus