[3] Hesperocyon, which lacks the shared derived characters that would include it within any of the aforementioned clades, is possibly ancestral to many of the lineages.

Some evidence indicates the Paraenhydrocyon clade may be directly descended from Hesperocyon gregarius.

According to Xiaoming Wang, Hesperocyon coloradensis provides an important link between H. gregarius and the Mesocyon-Enhydrocyon clade.

[3] According to an analysis of the fossil record of North American fossil carnivorans, the decline of hesperocyonines to extinction during the period from about 20 to 10 million years ago was driven by competition with felids and borophagines.

This article related to prehistoric animals from order Carnivora is a stub.