Revista de la Asociación Geológica Argentina
versión ISSN 0004-4822
Toxodon is the first extinct native ungulate to be described; it is the last representative of this extraordinary race, which since its discovery proved its uniqueness and its strong differentiation of the other orders of ungulates then known. Precisely the features that seemed to connect Toxodon with diverse groups of mammals (rodents, Perissodactyla, and Sirenia), were not indicators of kinship but these peculiar traits of native extinct ungulates, denoting the artificiality of forcing its location in systematic hierarchies then known. Owen first, and Roth definitely will understand the meaning of the singularities of Toxodon and allied forms, including them in a separate group of extinct mammals of South America, the Notoungulata.
Palabras llave : Native ungulates; Taxonomy; South America.