Hyracodon Rhino Relative Fossil Skull

Description: Members of genus Hyracodon (meaning hyrax tooth) is an extinct mammal of the order Perissodactyla. It was lightly built, resembling a pony some five feet long. Hyracodon's skull was large in comparison to the rest of the body. This comparatively small, swift animal was a close relative of the largest land mammal that ever lived, the 26 foot tall Paraceratherium. This specimen is the upper portion only of the skull.

Members of Order Perissodactyla (called the the odd-toed ungulates) appeared in what is now North America during the late Paleocene, some 10 million years after the Cretaceous -Tertiary extinction event in which the dinosaurs died out. By the start of the Eocene ) they had diversified and spread out to occupy several continents. Rhinos and zebras are also members of the order.

E. D. Cope On the Extinct American Rhinoceroses and Their Allies, The American Naturalist, Vol. 13, No. 12 (Dec., 1879), pp. 771a-771j.