Creodonts
The fossil skeletons of creodonts Oxyaena (top) and Hyaenodon (bottom)
"The creodonts, the main meat-eaters in North America, Europe and Asia in the early Tertiary, ranged from stoat- to bear-sized. Sinopa, an early fox-like creodont [skull pictured below], has a low skull and all of its cheek teeth are sharpened for cutting flesh. Oxyaena, a rather cat-like animal, has a long body and short limbs, retaining five toes on each plantigrade foot. Hyaenodon, representing a different creodont group, was larger, and some of its relatives reached bear size. This wolf-like animal was the only creodont to survive the late Eocene, living in Africa and Asia until the Late Miocene. Cladistic analyses (Polly, Journal of Vertebrate Palaeontology, 16, p303, 1996) suggest that the creodonts are probably a polyphyletic assemblage, including relatives of the modern Carnivora, as well as other lines with no living relatives."
| Machaeroides eothen skull, a small sabre-toothed creodont from the Eocene, American Museum of Natural History, New York |  |