Biological strategies of living conservative mammals

摘要

There exists some difficulty among biologists concerning the definition of the word "primitive." For my purposes, I consider primitive to be synony-mous with the possession of a set or sets of conservative (or plesiomorph) characters. Such conservative characters include not only aspects of mor-phology but also conservative physiological and behavioral traits. It is axio-matic then that the possession of such a conservative set of phenotypic characters implies that the animals very probably are occupying habitats and exploiting them in a manner similar to those mammals that existed at the end of the Cretaceous.