Serpentine stories

The discovery of a fossilised backbone of 45 feet long snake in Colombia challenges our understanding of past climates and environments, writes Steve Connor

IT GREW up to 45ft long, weighed more than a ton and dined on giant turtles and fearsome crocodiles. It is also the biggest known snake to have ever lived — and even dwarfed the Hollywood serpent that tried to eat Jennifer Lopez in Anaconda.

Scientists discovered the fossilised backbone of the super-sized reptile in an opencast coalmine at Cerrejon, northern Colombia. They estimated that, at the fattest point on its long body, the snake would have been about 3ft wide. The extinct reptile, formally named Titanoboa cerrejonensis, lived about 60 million years ago, some five 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 life forms on the planet.

It weighed about 1.25 tons and would have been the top predator in its semi-aquatic habitat of rivers and forests, eating practically anything that moved, from large tarpon-like fish the size of sharks to crocodiles up to 20ft long.

Titanoboa cerrejonensis belonged to the group of non-venomous snakes, the constrictors such as boas and anacondas, which strangle and suffocate their prey with 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," said Jonathan Bloch of the University of Florida in Gainsville, a co-leader of the study published in Nature.

"The snake that tried to eat Jennifer Lopez in Anaconda is not as big as the one we found." He added, "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." 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," said Dr Polly. "The size is pretty amazing, but our team went a step further and asked: How warm would the Earth have to be to support a body of this size?" 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 that principle, and armed with the knowledge of what is known about snakes today, the researchers were able to estimate the average temperatures of the tropical region 60 million years ago.

The size of the snake indicates that it lived in an environment where the average yearly temperature was between 30`BAC and 34`BAC — about 5`BAC hotter than the average temperatures at Cerrejon in Colombia.

"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." Dr Jaramillo added, "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."

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 this species challenges our understanding of past climates and environments, as well as the biological limitations on the evolution of giant snakes."

— By arrangement with The Independent

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