Hyaenodon leptorhynchus Skull Replica measures 11x7x4.5 inches. Hyaenodon Skull Replica is museum quality polyurethane cast. Made in USA. 2-part skull (separate cranium and jaw). Oliogocene creodant. Our precise skull can be used as a teaching tool, museum skull exhibit, home décor skull, or office décor skull.

The last surviving family of the carnivorous order of mammals called Creodonta, hyaenodon leptorhynchus are best described as large, archaic predatory mammals that were widely and geographically distributed during the early Cenozoic.

Hyaenodon leptorhynchus were also the most specialized of all creodonts, and were well represented predators in the White River Badlands.

Like other predatory mammals, fossil hyaenodon leptorhynchus are not commonly collected but do show a variation of different sized species. Only the genus Hyaenodon survived into the Oligocene. All creodonts except Hyaenodon disappeared by the end of the Eocene.

Hyaenodon leptorhynchus were present in diverse endemic radiations in Europe and Africa until the late Miocene. White River hyaenodons, including Hyaenodon horribilis, gregarious and mustelinus, are typified by having big heads, large sagittal crests and broad temporal fossae.

With exaggerated dental shearing systems and a digitigrade mode of locomotion, Hyaenodon, especially the large H. horribilis, may have competed for similar species of prey as the large nimravids.

Lacking binocular vision however, may have placed them at a disadvantage when competing with other similar sized predators and some paleontologists feel they were more likely carrion eaters and thus similar in style to the modern day hyaena.

It has been observed that there is a species of hyaenodon leptorhynchus for each species of oreodont, perhaps their favorite prey, and when this family of primitive ungulates disappeared, hyaenodons did as well.

Hyaenodon leptorhynchus ranged from the size of a domestic dog (Hyaenodon cruentus) to that of a gray wolf (Hyaenodon horridus). Regardless, hyaenodons were primitive carnivores, their teeth adapted for eating meat but less specialized than those of the true carnivores.

Presumably better adapted to the opening, drying habitats of the late Eocene and early Oligocene than other creodonts, Hyaenodons all disappeared by the late Oligocene.

Studies on juvenile Hyaenodon specimens show that the animal had a very unusual system of tooth replacement. Juveniles took about 3–4 years to complete the final stage of eruption, implying a long adolescent phase.

In North American forms, the first upper premolar erupts before the first upper molar, while European forms show an earlier eruption of the first upper molar.