Hegetotherium is a small to middle-sized extinct genus of mammals, ranging from the size of rabbit (about 20-30 cm/12-16") to a beaver (about 3 ft/1 m) from the Early to Middle Miocene (Colhuehuapian-Colloncuran in the SALMA classification), through Pliocene sites of South America.

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.

[9][10] 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).

They reportedly have enlarged first upper incisors that are obliquely implanted in the prexamilla and lower teeth with a straight lingual face.