|An artist's rendition of the Titanoboa, which could have grown up to 15 metres long [Reuters]
The fossilised remains of the world's largest snake, a 15-metre, one tonne behemoth that included crocodiles among its favourite foods, have been found in a coal mine in northern Colombia.
The Titanoboa cerrejonensis, meaning titanic boa from Cerrejon, the region where the remains were found, roamed - or rather slithered – the Earth about 60 million years ago, scientists say.
Their findings are based on 180 fossils of vertebrae and ribs, which they believe came from more than two dozen individual snakes.
"It could easily eat something the size of a cow. A human would just be toast immediately"
Jack Conrad, snake expert
No skulls or teeth from the creature were found however.
An international team from the Panama-based US Smithsonian Tropical Research Institute said the fossils belong to the largest snake ever discovered, which could have weighed-in in excess of 1,100kg.
"It is a mind-bogglingly big snake," said Jason Head, a Smithsonian member and lead author of the fossil study.
Fed on crocodiles
Head, a palaeontologist at the University of Toronto Mississauga, said the finding challenged "the understanding of past climates and environments as well as the biological limitations on the evolution of giant snakes".
"This shows how much more information about the history of Earth there is to glean from a resource like the reptile fossil record."
|A handout photo showing an anaconda vertebrae, in white, dwarfed by the Titanoboa bone [AFP/Nature]
Scientists think the giant snake may have been the largest inhabitant of a hot, lush tropical rain forest which probably fed on crocodiles, large fish and big fresh water turtles.
It was not venomous and was likely a river-dweller akin to the large anacondas of today, wrapping around its prey.
Scientists also compared the fossil vertebrae to the radius-to-length ratio of living snakes to determine the size and weight of Titanoboa, a name derived from its current descendant, the boa constrictor.
Jonathan Bloch, the study's co-author and the Florida museum's curator of vertebrate paleontology, said a backbone from a five-meter anaconda was about the size of a silver dollar while a backbone from Titanoboa was the size of "a large Florida grapefruit".
Scientists think the largest Titanoboa may have been 15 meters or longer.
"This thing weighs more than a bison and is longer than a city bus," Jack Conrad, a snake expert with the American Museum of Natural History in New York who was familiar with the find, said.
"It could easily eat something the size of a cow. A human would just be toast immediately."
The largest known snake previously was Gigantophis, which lived about 40 million years ago in Egypt, and was at least 10 metres long.
The previous record among living snake species was held by a python that measured 10 meters and weighed 183 kilogrammes, the Smithsonian said.
The Titanoboa fossils were found inside the Cerrejon open-pit coal mine, in Colombia's northeastern region of Guajira.
Scientific estimates based on the size of the giant snake show that the average annual temperature in the tropical jungle it inhabited 60 million years ago was around 30-34 degrees Celsius.
"This temperature estimate is much hotter than modern temperatures in tropical rainforests anywhere in the world," said Carlos Jaramillo, a Smithsonian staff scientist and co-organiser of the excavations in Colombia.
"That means that tropical rainforests could exist at temperatures 3-4 degrees Celsius hotter than modern tropical rainforests experience."
The discovery of the giant snake fossils has stirred a lot of excitement as to its origin, which scientists say may have been the largest non-ocean vertebrate living at a time when the Earth was recovering from the mass extinction of dinosaurs.
Snakes first appeared about 99 million years ago.
Scientists also found fossils of prehistoric crocodiles and tortoises that they believe the Titanoboa may have fed on.
The study was to be published in the scientific journal Nature on Thursday.