April 16, 2008

Ancient Elephants Loved Water

Elephants, those large and lumbering landlubbers, used to live
partially in the water, according to new research.

A recent study found that an ancient elephant ancestor called
Moeritherium spent most of its time
in rivers and swamps.

Scientists knew that elephants are related to modern aquatic
creatures such as manatees, but they had never identified an ancient elephant
relative that lived in water. Now the evolutionary link is there.

"I think it's the first real evidence that there is a
semi-aquatic lineage to the elephants," said Alexander Liu, a graduate
student in paleobiology at Oxford University. "It's something that people
have expected but not been able to actually show."

Moeritherium had a
large body, small eyes set high on its long snout, and the very beginnings of
what would become a trunk.

Liu, along with Erik Seiffert of Stony Brook University and
Elwyn Simons of Duke University, analyzed the teeth enamel of Moeritherium, which lived in the Eocene epoch,
more than 37 million years ago. By measuring chemical signatures in the enamel,
the researchers were able to learn what the animal ate and whether its food
came primarily from land or water.

"We found that its diet was very similar to that of
fully aquatic animals," Liu told LiveScience.
"But we know they can't have been fully aquatic, because the bones we do
have show that it must have walked around and put weight on its feet."

The Moeritherium
fossils were found in Egypt, which would have been a tropical rainforest when the
animal was alive. The researchers think the creature might have had a lifestyle
similar to that of a hippo,
spending time in rivers and swamps, rather than a seafaring animal like a

It probably weighed about 500 to 700 pounds (225 to 350 kg). While
it didn't have very large ears or a trunk, it had a prehensile upper