This exhibit showcases the rich fossil history of the American Pronghorn Antelope. See the dozens of species of pronghorn that have existed in the past several million years. Today all that remains of this original American family is one species, unrelated to the African antelope with which it is confused. The exhibit features actual fossils and skeletons as well as life sized reconstructions of extinct pronghorns. Prehistoric Pronghorn comes to AzMNH from the International Wildlife Museum in Tucson.

Modern pronghorns inhabit the deserts and dry grasslands of western North America. They are medium-sized animals, measuring from 3-4.5 feet in length and weighing up to 100 pounds. Their body is stocky and they have long, thin legs. Their coat is pale brown with a whitish belly and rump, and they have distinctive black and white markings on their heads and necks. The horns are erect and consist of two branches or prongs, a short branch extending forward and located about halfway up the horn and a longer, backwardly directed tip.

Pronghorn antelopes are among the fastest long-distance runners, achieving bursts of speed up to 60 miles per hour, and they are able to maintain speeds in excess of 30 mph for distances of several miles. Pronghorns are found in small herds or bands during the summer, and in larger groups of up to 100 individuals in winter. Their herds have a well developed social hierarchy.

Today only one species exists in the family Antilocapridae, but the group has a fossil record dating to the Miocene, about 20 million years ago. During its history, the Antilocapridae has included a variety of species, some of which had multiple and bizarre horns. The exhibition features a pronghorn family tree, which features some of these distinctive animals.

In 2005, the Arizona Museum of Natural History excavated two tusks and a neck vertebra, probably from one or more Columbian Mammoths, in the city of Gilbert, Arizona. In addition to ancient elephant, paleontologists found fossil horse, llama, tortoise, and a single tooth of Stockoceros, a prehistoric pronghorn. The mural, by artist Craig Chelpy, shows fauna of the Plio-Pleistocene (2.5 million years to 10,000 years ago), including American lion, camel, horse, peccary, tortoise and sloth, in a landscape that might well have included ancient pronghorn. The case below displays the fossils.

Stockoceros is known from three localities in Arizona: the original site of Papago Springs Cave, Ventana Cave, and the Gilbert mammoth site.