Sespe Eocene didelphids

In segregating a number of tiny insectivore and primate jaws from the Sespe deposits of California, several specimens were noted that clearly belong to marsupials. These are all incomplete but possess interest because they record didelphids for the first time in the North American upper Eocene and secondly because this group of mammals has not been known heretofore in Tertiary faunas west of the Rocky Mountains except for a single occurrence in the upper Oligocene John Day assemblage of north-central Oregon.