Sunday, 15 May 2011
The largest snake the world has ever known -42 to 45 feet long -ruled tropical ecosystems only 6 million years after the disappearance Tyrannosaurus rex, according to a new discovery in Columbia of the fossil skeletons of a giant, boa constrictor-like snake, named Titanoboa cerrejonensis. Tipping the scales at an estimated 1.25 tons, the snake lived during the Paleocene Epoch, a 10-million-year period immediately following the extinction of the dinosaurs 65 million years ago.
"Truly enormous snakes really spark people's imagination, but reality has exceeded..
the fantasies of Hollywood," said Florida Museum vertebrate paleontologist Jonathan Bloch , who co-led the expedition with Carlos Jaramillo, a paleobotanist from the Smithsonian Tropical Research Institute in Panama. "The snake that tried to eat Jennifer Lopez in the movie 'Anaconda' is not as big as the one we found."
Jason Head, a paleontologist at the University of Toronto in Mississauga and the paper's senior author, described Titanoboa this way: "The snake's body was so wide that if it were moving down the hall and decided to come into my office to eat me, it would literally have to squeeze through the door."
During the expedition, the scientists found many skeletons of giant turtles and extinct primitive crocodile relatives, the 7-foot-long (2.1-meter-long) Cerrejonisuchus improcerus—which wouldn't have stood a chance against the 45-foot-long (13.7-meter-long) Titanoboa cerrejonesis.
"Prior to our work, there had been no fossil vertebrates found between 65 million and 55 million years ago in tropical South America, leaving us with a very poor understanding of what life was like in the northern Neotropics," Bloch said. "Now we have a window into the time just after the dinosaurs went extinct and can actually see what the animals replacing them were like."
The snake's gigantic dimensions are a sign that temperatures along the equator were once much hotter, Bloch said. Snakes and other cold-blooded animals are limited in body size by the ambient temperature of where they live.
"If you look at cold-blooded animals and their distribution on the planet today, the large ones are in the tropics, where it's hottest, and they become smaller the farther away they are from the equator," he said.
"Based on the snake's size, the team was able to calculate the mean annual temperature at equatorial South America 60 million years ago was about 91 degrees Fahrenheit, about 10 degrees warmer than today," Bloch said.
The presence of outsized snakes and freshwater turtles shows that even 60 million years ago the foundations of the modern Amazonian tropical ecosystem were in place, he said.
Harry W. Greene, a professor in the department of ecology and evolutionary biology at Cornell University and one of the world's leading snake experts, said the "colossal" ancient boa researchers found has "important implications for snake biology and our understanding of life in the ancient tropics."