Featured in this lot is this Hyaenodon Horridus fine lower jaw and teeth fossil circa the Upper Oligocene (over 25 million years old). The fossil shows a wonderfully and professionally preserved construction that shows in the fragments with two of the whole jaws smaller incisors present with parts of the back molars. The fossil is in five parts that can correctly fit together when carefully arranged. Hyaenodons are extinct carnivorous mammals that likely preyed on the oreodonts of the Oligocene. They had large skulls, short necks, very tiny brains, and ranged in size from that of a small dog to that of a large wolf. Though Hyaena is part of their name they have no relation to modern Hyaenas. The name more refers to the likely eating habits of these carnivores as carrion eaters. The condition of this Hyaendon Horridus lower jaw shows fragmenting to jaws structure and shows one of the smaller incisor, and shows the hind molar separated from the jaw. The measurements of the jaw as put together as possible is 6 1/4" x 10 1/2 x 1 1/2". The collective weight of this 4lbs.