Assuming the Earth today is not particularly unusual, Head and Dr Jonathan Bloch, Assistant Curator of Vertebrate Paleontology at the Florida Museum of Natural History, estimated a snake of Titanoboa's size would have required an average annual temperature of 30 to 34C (86 to 93 F) to survive. By comparison, the average yearly temperature of today's Cartagena, a Colombian coastal city, is about 28C.
"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 temperature estimation shows that a tropical rainforest, like Cerrejon, lived at a temperature of 32C, five degrees above the upper limit of temperature for tropical rainforest in modern times," said Carlos Jaramillo, a palaeobotanist ad the Smithsonian Topical Research Institute. "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."
The scientists classify Titanoboa as a boine snake, a type of non-venomous constrictor that includes anacondas and boas. Head and 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 vertebrae originate near Titanoboa's middle. That means that if Polly's model is incorrect about the bone's placement, the snake could have been even bigger.
Evolution has produced a wide variety of gigantic animals over the
|Contact: Sian Halkyard|
Queen Mary, University of London