Research published in Nature shows that climate changes and the highly specialized digestive system of the wild horse Equus ferus might have contributed to its extinction in North America.
COURTESY MARIE GILBERT
Guthrie's findings were based on measurements and radiocarbon dating of E. ferus cannon bones.
At the end of the Pleistocene epoch, E. ferus was abundant and wide-ranging in North America. However, E. ferus, which stood at about 14 hands, shrank about 12% before disappearing entirely around 12,500 years ago, according to R. Dale Guthrie, PhD, a professor emeritus at the University of Alaska, Fairbanks.
The disappearance of this species and other herbivores has long puzzled researchers, who have posed two conflicting theories for the extinctions–overhunting by humans or climate change.
New evidence found in the fossil record of Alaska seems to let people off the hook. E. ferus became extinct nearly 600 years before undisputed archaeological evidence of human hunters in the region. Guthrie based his findings on measurements and radiocarbon dating of the cannon bones of mature animals from th