We're used to thinking of Pronghorns—our so-called antelope—as being moderately large. And that's true of the modern species. However, this sole species of pronghorn is merely the last of a distinguished line that otherwise died out only about 11,000 years ago.
Included among the several ice age pronghorns was one so small that we would hardly recognize it as being one of the artiodactyls—the group that includes deer, cattle, and sheep. One paleontologist described this delicate creature as not being much larger than a jack rabbit, though perhaps that's hyperbole. Nevertheless, at somewhere around 1½ to 2 feet tall at the shoulders, it hardly fits our mental image of grazers.
This Diminutive Pronghorn also disrupts our sense of fitness in another way. Unlike any living horned mammal, it had a pair of small horns in addition to a larger pair. Perhaps it's the modern
Pronghorn that's out of step, though. Other ice-age relatives had four large horns, and an earlier species boasted of six—so let's pity our poor, deprived survivor. 
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.
