Description: The Rhonoceraids are divided into two groups: the cursorial (running) Hyracodontidae, the aquatic Amnyodontidae, and the true rhinoceroses Rhinoceratidae. The first two groups are known only from fossils while there are several true rhinos found in Africa and Asia today. This is the mandible (lower jawbone) of a cursorial rhino known as Hyracodon nebrascensis. It was found just last week by the avocational paleontologist Frank Garcia. Note the in situ photos included. Given its size and the fact that a newly-erupted adult molar can be seen at the back of the jaw this is a juvenile example of this sheep-sized rhino. Note also the forepart of the jaw. It has a pathology as can be seen from the displacement and malformation seen in both buccal (cheek) and lingual (tongue) views. This malformation could well have led to the early demise of this unfortunate individual. Notice the translucent quality to the incisors. The shine to the specimen is due to use of Paleobond as a sealant to consolidate and stabilize the specimen. See my other offerings for a single molar tooth of the same taxon.