 The name "Hexaprotodon" means "six front teeth" as some of the fossil forms have three pairs of incisors.The genus "sensu lato", including African taxa, has been suggested to be paraphyletic with respect to both species of living hippopotamus.The uncontroversial, core asian members of the genus most closely related to the type "S. sivalensis" were widespread throughout the Late Neogene and Quaternary of South and Southeast Asia, with the oldest records coming from the Late Miocene Siwaliks.