Allochthon(redirected from Allochthonic)
Also found in: Dictionary.
an organism inhabiting some locality which, unlike an autochthon, arose in the course of evolution in some other place. It reached the regions inhabited at the present time by migrating from its own original center of distribution. For example, the opossum and several hummingbird species are allochthons of North America, which they entered from South America.