Herpetotheriidae is an extinct family of metatherians. Although sometimes placed in the living opossum family (Didelphidae, as a subfamily Herpetotheriinae), they may form the sister clade to all living marsupials. Species of this family are generally reconstructed as terrestrial. 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 and the youngest member is Amphiperatherium from the Middle Miocene of Europe.