To be stealthy, you gotta suck

At least according to a new report released by scientists studying Dinocephalosaurus, a long-necked aquatic reptile that lived in what is now China some 230 million years ago.

"The long neck would allow it to approach prey without the whole body becoming visible," Olivier Rieppel of the Field Museum in Chicago, a co-author of the report, said in a telephone interview.

Which is good (for the Dinocephalosaurus, not the fish), but it may have done even better than that. Ever notice how when you try to catch or swat certain insects, they seem to know and escape at the last second, even if you sneak up on them? Some insects have organs that sense air pressure, like the wave of air that arrives a split second before the rolled up newspaper. Fish have that ability too, and water, being much more dense than air, telegraphs the pressure wave even more noticably (try it in a swimming pool or bathtub, you'll see what I mean). So how did Dinocephalosaurus solve that little problem?

Michael LaBarbera of the University of Chicago, a co-author of the report, said the rib-like bones along the side of the neck may also have played a role in hunting.

Those bones give the neck some stiffness, Rieppel explained. It could flex, but not like a snake.

According to LaBarbera, contraction of the creature's neck muscles could have rapidly straightened the neck and splayed the neck ribs outward.

That would have greatly increased the volume of the throat, allowing the animal to lunge forward in the water at prey. Ordinarily, lunging through water creates a pressure wave that a fish can sense, allowing it to flee. But the researchers said that by suddenly enlarging its throat Dinocephalosaurus could, in effect, suck in and swallow its own pressure wave, giving it the ability to strike without warning.

The original Big Gulp. Nature does some amazing things.

Posted by Ted at September 24, 2004 06:01 AM | TrackBack