Herpetotheriidae is an extinct family of metatherians, closely related to marsupials.[1] Species of this family are generally reconstructed as terrestrial, and are considered morphologically similar to modern opossums.[2] Fossils of herpetotheriids come from North America, Asia, Europe, Africa, and perhaps South America. The oldest representative is Maastrichtidelphys from the latest Cretaceous (Maastrichtian) of the Netherlands[3] and the youngest member is Amphiperatherium from the Middle Miocene of Europe.[4] The group has been suggested to be paraphyletic, with an analysis of petrosal anatomy finding that North American Herpetotherium was more closely related to marsupials than the European Peratherium and Amphiperatherium.[5]