The Oldest Rabbit

New rabbit fossils dating to about 55 million years ago suggests rabbits and rodents diverged from other placental mammals about 65 to 70 million years ago.

The finding is presented in today's issue of the journal Science.

The new fossil skeletons from the ancient rabbit species Gomphos elkema could also help clarify which animals in the fossil record are the close relatives of modern mammals and which are not. In particular, scientists found that modern rabbits and rodents are not closely related to "zalambdalestids" -- a group of animals that are known to be over 85 million years old.

The illustration above shows what researchers think the animal looked like. It was similar in size to a squirrel you might find living in New York City's Central Park.

Discovered in southern Mongolia, the new fossils include a complete specimen that extends knowledge of rabbit skeletal anatomy by about 20 million years. In contrast to modern rabbits, these ancient rabbit-relatives had primitive teeth and jaws.

Ancient rabbits moved around like modern rabbits, the scientists say, thanks to elongated hindlimbs and a very long "rabbit's foot."

-- LiveScience Staff