"Ancient" Horse from Kansas Is Actually Recent Domestic Horse, Say Scientists

A horse skull and jaw from Lawrence, Kansas, named as a new species of Ice Age horse almost a century ago and long considered to be of great antiquity, have recently been determined by scientists to be less than 400 years old.

The new interpretation was advanced by a team of paleontologists from California, Colorado and Kansas. The results of their investigations will be presented Friday, October 17, at a professional scientific meeting in St. Paul, Minnesota.

The purported Ice Age horse species was named Equus laurentius, in honor of the skull and jaw having been found near Lawrence, Kansas in 1910. The bones, first described in 1913, were thought to date to the Pleistocene Epoch, a period of time commonly termed the "ice ages" that began almost two million years ago and ended about eleven thousand years ago.

The new study sought to determine the precise age of the bones using an advanced form of carbon dating called accelerator mass spectrometry. The results showed that the skull dated to only about 300 years old, while the lower jaw dated to approximately 240 years old.

"This was an exciting find," said paleontologist Eric Scott of the San Bernardino County Museum in Redlands, California, the lead scientist of the study. "Some scientists in the past have voiced suspicions about this species, because the bones looked an awful lot like a modern horse. Our dates make it clear that we're dealing with relatively recent bones, not Ice Age fossils."

The youth of the bones was further emphasized by evidence suggesting that the horse held a bit in its mouth during its life.

"We found unusual wear patterns on some of the grinding teeth of the lower jaw," explained Scott. "We don't know of any similar patterns in modern wild horses or in fossil horses. And the worn areas correspond to where a bit would rest in a modern horse's mouth - behind the canine teeth, but in front of the grinding teeth."

The study also determined that the skull and jaw were most likely from two different individuals. This finding had been suggested for the specimen before, but the present study applied new techniques that analyzed the protein chemistry and isotope composition of the bone. These analyses, conducted by Thomas Stafford, Jr., of Stafford Research Laboratories in Boulder, Colorado, the lab that also provided the carbon dates, strongly indicated that the jaw and skull were from different animals.

"I'd estimate that the skull and jaw could be separated in age by a few years to a few decades at most," says Stafford.

Other scientists contributing to the study were paleontologists Russell Graham of the Denver Museum of Nature and Science and Larry Martin of the Kansas University Natural History Museum in Lawrence. Stafford and Graham had originally dated the jaw as part of a larger study to investigate the timing and sequence of Pleistocene extinctions in North America. The present study augmented those dates with dates from the skull, along with a detailed examination of the anatomy of the specimen.

The new study makes clear the importance of new techniques in the study of old bones, says Scott. It also emphasizes the importance of preservation. "People often wonder why museums hold on to some of these old fossils," he observed. "As technology moves forward, and our understanding grows, we can learn more and more about some of these fossils that have been around for decades. But unless museums are actively preserving these finds for future generations, such studies may never happen."

The San Bernardino County Museum is at the California Street exit from Interstate 10 in Redlands, California. The museum, with collections and exhibits focused on the cultural and natural history of inland southern California and the Southwest, is open Tuesdays through Sundays from 9 a.m. to 5 p.m. For more information, visit www.sbcountymuseum.org or call (909) 307-2669 / TDD/TTY: (909) 792-1462.