Assuming the Earth today is not particularly unusual, Head estimated a snake of Titanoboa's size would have required an average annual temperature of 30 to 34 C (86 to 93 F) to survive. By comparison, the average yearly temperature of today's Cartagena, a Colombian coastal city, is about 83 F.
"Tropical ecosystems of South America were surprisingly different 60 million years ago," said Bloch. "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 tropical rainforest at Cerrejon appears to have thrived at a temperature of 32 C, five degrees warmer than the upper temperature limit for tropical rainforests in modern times. "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," said Carols Jaramillo, a palaeobotanist at the Smithsonian Topical Research Institute.
Evolution has produced a wide variety of gigantic animals over the last several hundred million years -- dinosaurs, ancient dragonflies and today's blue whale, to name a few. Why some species' lineages produce monsters remains a matter of debate among evolutionary biologists and ecologists.
The scientists classify Titanoboa as a boine snake, a type of non-venomous constrictor that includes anacondas and boas.
Polly extrapolated the placement of Titanoboa fossil vertebrae by comparing the fossils' structure to the vertebrae of today's boine snakes. Snake vertebrae get bigger near a snake's midsection, but they are also structured differently than vertebrae closer to a snake's head or tail. Using a computer model he wrote, Polly estimated the fossil
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