Ancient Long-Necked Reptile Was Stealthy Suction Feeder

Scientists have unearthed the fossil of an ancient aquatic reptile that
sported a neck almost twice as long as its meter-long body. The
1.7-meter-long neck appears to have been too rigid to twist around in search
of prey, however, so its function was at first uncertain. "This animal was
one of those things that comes along and says 'wait a minute, you don't know
as much as you thought you did'" about what long necks are good for, says
Michael LaBarbera of the University of Chicago, one of the authors of a
paper detailing the find published today in Science.

The Guanling limestone formation in China, where the new specimen was found,
was deposited on the ocean floor about 230 million years ago in the Triassic
period, when dinosaurs were becoming prevalent on land. The fossil belongs
to the carnivorous species Dinocephalosaurus orientalis, which scientists
first described only last year. It is a protorosaur, a group of reptiles
that includes Tanystropheus, whose ludicrously long neck has stimulated
debate since its discovery in the 1850s. Unlike Tanystropheus, however,
Dinocephalosaurus had flipper-shaped limbs, indicating a largely aquatic
lifestyle.

The authors suggest that the long, thin neck enabled Dinocephalosaurus to
sneak up on prey in murky water without revealing its full size. In
addition, the 25 neck vertebrae bore ribs running along the spine.
Straightening the spine and extending the ribs could have rapidly increased
the volume of the neck, sucking in both prey and water. Some modern fish
rapidly expand their mouths to accomplish a similar "suction
feeding." --Don
Monroe

Full Text at Scientific American
http://www.sciam.com/article.cfm?chanID=sa003&articleID=00006FCD-4E7A-1153-8E7A83414B7F0000

Posted by
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