"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.