The snake that was so big it ate crocodiles

It grew up to 45 feet long, weighed more than a ton and dined on giant turtles and fearsome crocodiles. It was also the biggest known snake to have ever lived - even dwarfing the Hollywood snake that tried to eat Jennifer Lopez in the film Anaconda.

Scientists discovered the fossilised backbones of the super-sized snake in a giant open-cast coal mine at Cerrejon in northern Colombia and estimated that at the fattest point on its very long body the snake would have been about three feet wide.

It lived about 60 million years ago, some 5 million years after the demise of the last dinosaurs, and before the warm-blooded mammals had been able to establish themselves as the largest and most widespread animal lifeforms on the planet.

Related articles

• More Science News
• Search the news archive for more stories

The extinct reptile, formally named Titanoboa cerrejonensis, weighed about 1.25 tons and would have been the top predator in its semi-aquatic habitat of rivers and forests where it would have eaten practically anything that moved, from large tarpon-like fish the size of sharks to extinct crocodiles up to 20 feet long.

It belonged to the group of non-venomous snakes -- the constrictors such as the boas and anacondas -- which strangle and suffocate their prey with their immense body muscles before devouring them whole, possibly with the help of the loosely-reticulated skulls and jaws seen in present-day constrictors.

"Truly enormous snakes really spark people's imagination, but reality has exceeded the fantasies of Hollywood. The snake that tried to eat Jennifer Lopez in the movie Anaconda is not as big as the one we found," said Jonathan Bloch of the University of Florida in Gainsville, a co-leader of the study published in Nature.

"Tropical South America was surprisingly different 60 million years ago. It was a rainforest like today, but it was even hotter and the cold-blooded reptiles were all substantially larger. The result was, among other things, the largest snakes the world has ever seen, and hopefully ever will," Dr Bloch said.

The researchers estimated the overall size and weight of the snake from several vertebrae excavated in the coal mine and by comparing them to living snakes from the same group of constrictors, said David Polly of Queen Mary, University of London, who used computer models to gauge its overall size.

"At its greatest width, the snake would have come up to about your hips. The size is pretty amazing, but our ream went a step further and asked, how warm would the Earth have to be to support a body of this size," Dr Polly said.

A general rule for cold-blooded animals is that they get bigger the nearer they live to the equator, and the warmer the ambient temperatures are. Based on this principle, and armed with the knowledge of what is known about snakes today, the researchers were able to estimate the average temperatures of this tropical region 60 million years ago.

The size of Titanoboa indicates that it lived in an environment where the average yearly temperature was between 30C and 34C, which is about 5C hotter than the average temperatures at Cerrejon in Colombia today.

"This temperature estimate is much hotter than modern temperatures in tropical rainforests anywhere in the world," said Carlos Jaramillo of the Smithsonian Tropical Research Institute in Panama, the other co-leader of the research team.

"The fossil floras that the Smithsonian has been collecting in Cerrejon for many years indicate that the area was a tropical rainforest. That means that tropical rainforests could exist at temperatures of 3C to 4C hotter than modern tropical rainforests experience," Dr Jaramillo said.

"These data challenge the view that tropical vegetation lives near its climatic optimum+ and it has profound implications in understanding the effect of current global warming on tropical plants," he said.

Jason Head, professor of ecology and evolution at the University of Toronto, said the higher temperatures of the Cerrejon rainforest 60 million years ago question many assumptions. "The discovery of Titanoboa challenges our understanding of past climates and environments, as well as the biological limitations on the evolution of giant snakes," Dr Head said.

"The snake's body was so wide that if it were moving down the hall and decided to come into may office to eat me, it would literally have to squeeze through my door," he said.