Reigitherium

Reigitherium bunodontum is a mammal that lived during the Late Cretaceous (Late Campanian-Maastrichtian). Fossils of it have been found in the Los Alamitos and the La Colonia Formations of Argentina.[1]

Reigitherium was initially classified in the order Dryolestida.[2] In 2000 Pascual et al. found it to be a Docodont. Later authors found it to be neither a Dryolestoid nor a Docodont, and found it to be of uncertain placement within Mammalia.[3][4] In 2011, Rougier et al. found it to be a Dryolestoid again, within Meridiolestida, a clade composed of Gondwanan Dryolestoids.[5] It "differs from other Mesozoic mammals including docodontans in that the lower molars decrease in length and notably increase in width posteriorly."