FOSSIL CARNIVORA a5 
MESONYCHID2. 
Type: Mesonyx, skull etc, Wall-case No. 6. 
These animals had the limbs and feet specialized for swift 
running, and the feet tipped with flat hoof-like claws. The teeth 
are quite peculiar, they have no shearing edges, and the crown 
is composed of three rather high blunt-topped conical cusps. In 
FIG. 12. SKULL OF MESONYX 
Upper Eocene of Utah. After Osborn 
the upper jaw these are in a triangle, one cusp inside, two out- 
side; in the lower jaw they are in series, the central one being 
much the highest. 
The Mesonychide are found in all the Eocene strata from the 
oldest to the youngest, and show a series illustrating the gradual 
evolution of their peculiar type of tooth. The massive blunt- 
cusped teeth, generally very much worn, suggest that they were 
used for crushing bones or other hard food, and that the animal 
fed upon carrion, like the modern hyzna. (See Fig. 1.) 
