Biggest Snake Discovered; Was Longer Than a Bus

John Roach
for National Geographic News
February 4, 2009
The world's biggest snake was a massive anaconda-like beast that slithered through steamy tropical rain forests about 60 million years ago, says a new study that describes the ancient giant.

(See pictures of the ancient giant and other huge snakes and watch video.)

Fossils found in northeastern Colombia's Cerrejon coal mine indicate the reptile, dubbed Titanoboa cerrejonesis, was at least 42 feet (13 meters) long and weighed 2,500 pounds (1,135 kilograms).

"That's longer than a city bus and … heavier than a car," said lead study author Jason Head, a fossil-snake expert at the University of Toronto Mississauga in Canada and a research associate with the Smithsonian Institution.

Previously the biggest snake known was Gigantophis garstini, which was 36 to 38 feet (11 to 11.6 meters) long. That snake lived in North Africa about 40 million years ago.

Hans-Dieter Sues, associate director for research and collections at the Smithsonian's National Museum of Natural History, was not involved with the study but has seen the snake fossils.

Sues noted that humans would stand no chance against one of these giants, which killed their prey by slow suffocation.

"Given the sheer size—the sheer cross-section of that snake—it would be probably like one of those devices they use to crush old cars in a junkyard," Sues said.

In addition, the snake's heft indicates that it lived when the tropics were much warmer than they are today, a find that holds potential implications for theories of once and future climate change.

Biggest Snake Needed the Heat

Scientists know there's a link between a snake's body size, how fast it uses and produces energy, and climate.

(Related: "World's Smallest Snake Discovered, Study Says" [August 3, 20008].)

"We were able to use the snake, if you will, as a giant fossil thermometer," study author Head said.

His team found that, for Titanoboa to reach its epic proportions, mean year-round temperatures would have been about 90 degrees Fahrenheit (32 degrees Celsius)—significantly hotter than today's tropics.

This supports the idea that tropical temperatures spike as the rest of the world heats up due to global warming, the study authors say.

The competing theory is that, during bouts of warming, the tropics stay about the same average temperatures as they are today while areas north and south of the Equator heat up.

James Zachos, an expert on ancient climates at the University of California, Santa Cruz, who was not involved in the study, agreed.

As the biggest known snake, Titanoboa supports the idea of "much hotter tropics during extreme greenhouse periods," Zachos said.

Big Reptiles on the Horizon?

Study co-author Jonathan Bloch is a vertebrate paleontologist at the University of Florida's Museum of Natural History in Gainesville.

The same Colombian coal mine that contained the biggest snake also yielded massive turtles and crocodiles, he said.

"You can think about it as an ecosystem dominated by giants, I think, and these are probably giants that got large because of the warmer mean annual temperature," he said.

The findings, detailed in this week's issue of the journal Nature, paint a picture of what the future might hold if supercharged global warming takes place.

According to some models, global temperatures could approach the same levels that gave rise to the biggest snake by the end of this century.

If current greenhouse gas emissions continue apace, there's a chance snakes the size of Titanoboa could return, Bloch said.

"Or maybe snakes would go extinct in the tropics," he said. "In other words, the warming could happen so rapidly that they wouldn't have time to adapt."

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