Harlan’s Muskox, Bootherium bombifrons

Harlan’s muskox (Bootherium bombifrons) is an extinct type of bovine, also known as the woodland muskox.  It lived in North American during the late Pleistocene era, and was one of the most widely distributed oxen at that time. This bison died out around 11,000 years ago.

Many fossils of Harlan’s muskox have been found in New Jersey, Texas, Oklahoma, Alaska, and California, including a nearly complete individual found in 1940. Three other types of muskoxen inhabited North America along with Harlan’s muskox in the Pleistocene era, including the now extinct shrub-ox, the modern tundra muskox, and Soergel’s ox. The closest living relative of Harlan’s muskox is the extant muskox (Ovibos mochatus).

Harlan’s muskox differs from the tundra muskox in that it had adapted to weather that was less cold, and it was the only ox to have evolved and endured in North America. It was taller and leaner than modern Arctic muskoxen, and its skull was also considerably larger. The nose of Harlan’s muskox was longer as well. There are differences in horn structure between modern oxen and Harlan’s muskox, including the means of attachment. The horns of a Harlan’s muskox are attached to the midline of the skull, whereas modern tundra muskoxen horns are attached by a medial groove.

Image Caption: Cast of Bootherium bombifrons’ (Harlan’s musk ox) skeleton, assembled from specimens found in several states. Indiana State Museum, 650 West Washington Street, Indianapolis, Indiana, USA. Credit: Wikipedia