The didelphomorphs are a group of American marsupials that include modern opossums. However fossil evidence suggests that possibly this group extends far back into the Cretaceous. Many opossum-like marsupials have been found in the Late Cretaceous and occassionally in the early Cenozoic era; if the families Peradectidae, Stagodontidae, Herpetotheriidae, and other examples are true didelphomorphs. Additionally if the above families are indeed didelphomorphs, then not only is this order ancient, but it extended into Europe and Asia as well as North and South America. These groups died out ultimately, leaving the Virginia opossum as the only northerly didelphimorph, an immigrant from South America. Conventionally these families are placed in this order until further evidence places them elsewhere. The most definite example of opossum-like marsupial skeletons have been found in the early Paleocene of South America.