August 1, 2009

Scientist: Giant snake no guide to climate

A California scientist disputes a theory that a giant snake that lived about 60 million years ago needed a warm climate to survive.

Mark Denny, a professor of marine sciences at Stanford University, argued the 40-foot-long snake could have regulated its body temperature by coiling up, The Stanford University News reported Friday.

Scientists at the University of Toronto discovered the fossil last year in an open-pit mine in Colombia. They estimate the length at 40 feet and weight at more than 2,000 pounds, which would make Titanoboa cerrejonensis a relative of the much smaller boa constrictor, the largest snake known.

The Toronto scientists said the snake would have needed a warm climate to survive, several degrees higher than previous estimates for the mean annual temperature in the Paleocene epoch.

But Denny used metal snakes in a wind tunnel and concluded coiling would have worked to preserve heat. His findings are to be published in Nature, which also published the Toronto scientists.

We suggest that the huge ancient snake was big enough to open up an avenue of behavioral regulation that's not there for smaller snakes, in which case the giant snake becomes an unreliable paleo-thermometer, Denny said.