Mesotherium
/ˌmɛsə(ʊ)ˈθɪərɪəm/Palaeontology
noun
A genus of large notoungulates known from fossils of the Pliocene and Pleistocene epochs in South America; a notoungulate of this genus.
Origin
Late 19th century. From scientific Latin Mesotherium, genus name from meso- + -therium.