Abstract
The pyrotheres are an extinct order of Paleocene-Oligocene South American mammals and encompass six valid genera: Carodnia Simpson, Carolozittelia Ameghino, 1901; Proticia Patterson, 1977; Colombiterium Hoffstetter, 1970; Propyrotherium Ameghino, 1901; and Pyrotherium Ameghino, 1889. Pyrotheria is a monophyletic order of mammals united with the Dinocerata in the monophyletic Mirorder Uintatheriamorpha. Thus, the pyrotheres are not members of the Ungulata, and their inclusion in the group as members of the Mirorder Meridiungulata should be discontinued. A phylogenetic relationship between pyrotheres and dinoceratans implies dispersal of the common ancestor of North American dinoceratans and South American pyrotheres during the Paleocene , prior to the Riochican. Paleocene volcanism in the Caribbean provided an archipelago for the dispersal of the common ancestor of dinoceratans and pyrotheres.