Rare Large Hyaenodon Bone Pieces, Hyaenodon horridus, Fossils, Oligocene, K304

Description

Type: This is a collection of fossil bones from the Hyaenodon,
Hyaenodon horridus
, (largest size).
This selection was all found together and comes from the same individual.  I can see an upper molar, a small premolar and some partial teeth.  The bones seems to be parts of an upper skull.  There are cheek fragments, some with tooth impressions.  There is also some parts of the top of the skull as I can see squiggly suture marks where the skull would have fused during growth.   Hyaenodon material is very uncommon to come across.  Will make a nice addition to the collection.
Locality: Private land in Pennington County, South Dakota
Age: Oligocene, 30 Million Years Ago
Ruler increments are 1/16 inch.
Your fossil will be sent with your invoice receipt in a padded bubble mailer, with ID label by USPS First Class Mail with Delivery Confirmation.
International buyers should contact me about international shipping of multiple items before paying as the price is based on the total weight of the items.
Hyaenodontidae - The last surviving family of the carnivorous order of mammals called Creodonta, hyaenodons are best described as large, archaic predatory mammals that were widely and geographically distributed during the early Cenozoic. Hyaenodons were also the most specialized of all creodonts, and were well represented predators in the White River Badlands. Like other predatory mammals, fossil hyaenodons are not commonly collected but do show a variation of different sized species. Only the genus Hyaenodon survived into the Oligocene (through the early Arikareean); other families of the order Creodonta first appeared in the mid-Paleocene but most had disappeared by the mid-Eocene. All creodonts except Hyaenodon disappeared by the end of the Eocene.
Hyaenodonts 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 sagital 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 for each species of oreodont, perhaps their favorite prey, and when this family of primitive ungulates disappeared, hyaenodons did as well.
Hyaenodons 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, perhaps in the face of competition from evolving canids, nimravids, and ursids.
Written by Alan S