Friday, December 13, 2013

New horse ancestor discovered in Ethiopia

The discovery of a new species of horse ancestor that is 4.4 million years old was reported by an international team of paleontologists and biologists in the Dec. 12, 2013, issue of the Journal of Vertebrate Paleontology.

Eurygnathohippus woldegabrieli was about the size of a small zebra. Portions of the ancestral horse have been discovered in the Middle Awash Valley in the Afar rift area of Ethiopia since 1987.

The most recent discovery of a front leg bone enabled the team to define the animal as a unique species. The bones discovered to date include teeth, foot bones, and leg bones.

The minimal fossil remains were sufficient to date the animal to 4.4 million years ago and to define the animal as a never before known breed of ancient horse.

Eurygnathohippus woldegabrieli had longer legs that earlier horses found in the same areas of Ethiopia between 3.5 million and 5 million years ago. A comparison of the new horse’s anatomy with animals as old as 10 million years of age indicates this is a new species.

The horse had three toes and fed on grasses. The wear on the teeth of the horse and chemical analysis of the bones of the new species indicates that grasses were the major component of the animal’s diet. The longer legs probably evolved to aid the animal in escaping predators and in covering long distances in the once grassy area that is now desert.