Wikipedia
Oxyaenidae is a family of carnivorous mammals. Traditionally classified in the wastebasket taxon Creodonta, they are actually unrelated to other clades within that order, and are basal laurasiatheres. The group contains three subfamilies comprising ten genera.
North American oxyaenids were the first creodonts to appear during the late Paleocene, while smaller radiations of oxyaenids in Europe and Asia occurred during the Eocene. They were superficially cat-like beasts that walked on flat feet, in contrast to modern cats, which walk or run on their toes. Anatomically, characteristic features include a short, broad skull, deep jaws, and teeth designed for crushing rather than shearing, as in the hyaenodonts or modern cats.(Lambert, 163)
Oxyaenids were specialized carnivores that preyed on other terrestrial vertebrates, eggs and insects. They were capable of climbing trees, which is suggested by fossil evidence of their paws.