Hegetotherium is currently restricted to the type species, H. mirable, of which H. convexum, H. anceps, H. minum and H. andinum are synonyms, but also H. cerdasensis. "Hegetotherium" arctum was formerly assigned to this genus, but is clearly not a member of Hegetotheriidae. "Hegetotherium" novum was formerly referred to the closely related genus Prohegetotherium, but is now considered generically distinct from that genus.[9][10]
Description
Hegetotheres are characterised by enlarged first upper incisors , implanted obliquely in the premaxilla, and lower teeth have a straight lingual face. They were among the most recently diverging families of Typothere Notiungulates ( an extinct order of ungulates that inhabited South America). With there ear;y fossil record closely resembeling mesotheres.[11]
The Hegetotheres, belonging to notoungulate group, have hypselodont (ever-growing) teeth. They reportedly have enlarged first upper incisors that are obliquely implanted in the prexamilla and lower teeth with a straight lingual face.[12] Their hypselodont teeth indicate that hegetotheres ate low-growing vegetables in open habitats.[13]
^F. D. Seoane, S. R. Juñent, and E. Cerdeño. 2017. Phylogeny and paleobiogeography of Hegetotheriidae (Mammalia, Notoungulata). Journal of Vertebrate Paleontology 37(1):e1278547:1-13.
^Vizcaíno, Sergio F.; Kay, Richard F.; Bargo, M. Susana (2012). Early Miocene paleobiology in Patagonia: high-latitude paleocommunities of the Santa Cruz Formation. Cambridge New York: Cambridge University Press. ISBN978-0-521-19461-7.
