Elephants’ aquatic ancestor - April 15, 2008
Elephants share a common aquatic ancestor with manatees and dugongs, according to a paper released in PNAS.
“It has often been assumed that elephants have evolved from fully terrestrial ancestors and have always had this kind of a lifestyle,” says one of the study’s authors, Erik Seiffert of the Stony Brook University, New York (BBC). “Now we can really start to think about how their lifestyle and behaviour might have been shaped by a very different kind of existence in the distant past.”
Seiffert and colleagues analysed the composition of teeth from early elephant Moeritherium and appear to have confirmed previous suspicions that it was amphibious. “We now have substantial evidence to suggest that modern elephants do have ancient relatives which lived primarily in water,” says fellow author Alexander Liu, of the University of Oxford (press release).
In her paper, Liu notes that there have been morphological and paleontological suggestions of a common aquatic ancestor but “independent tests of this hypothesis have proven elusive”. However oxygen isotopes in teeth provide a potential solution as the ratio isotopes differs between aquatic and terrestrial animals.
Sure enough, teeth from Moeritherium and anther proto-elephant Barytherium show that it likely spent much of its time lolling around in water chopping on freshwater plants.
This isn’t the first time teeth have been used in this way. Back in 2000, UC Santa Cruz researchers reported that a large prehistoric rhinoceros seemed to have enjoyed a hippo-like lifestyle (press release). And last year researchers used teeth isotopes to show that a “small, stocky” beast that “looked similar to a mini deer” may have been an ancestor of the whale (Nature; subscription required).
More coverage
Elephant ancestors were semi-aquatic – Daily Telegraph
Ancient Elephant Ancestor Lived in Water, Study Finds – National Geographic
Ancient elephants loved water – LiveScience
Image: courtesy Luci Betti-Nash / Stony Brook University.
Comments
I believe that we humans and elephants have this in common. I believe in the aquatic ape theory. A branch of apes adapted to a semi-aquatic lifestyle. That explains why we are bipedal, nearly hairless, and the body fat. I just want to add to this that I love elephants!
Posted by: Toby | December 9, 2008 08:33 AM