Fossil snake discovered in India may have been the largest ever

Fossil remains discovered in India have been identified as belonging to an enormous, 47-million-year-old extinct snake. Though only a few of the animal’s vertebrae were recovered, researchers estimate that it could have been up to 15 metres long, putting it in contention for being the longest snake of all time.

Back in 2005, palaeontologists including Sunil Bajpai at the Indian Institute of Technology Roorkee were searching for fossils in a coal mine in Gujarat in western India.

“We were actually prospecting this locality for fossils of early whales,” says Bajpai, “but we found not just whales but a host of other vertebrate fossils, including those of snakes.”

Among these fossils was a collection of 27 vertebrae measuring up to 6 centimetres long and 11 centimetres wide. Due to their large size and the fact that their anatomy was somewhat obscured by sediment, these were first thought to belong to some sort of extinct crocodile, says Debajit Datta, also at the Indian Institute of Technology Roorkee.

After a closer analysis, Datta and Bajpai now believe the vertebrae belonged to an exceedingly large snake from an extinct family called the Madtsoiidae. Only the extinct species Titanoboa cerrejonensis, which had slightly larger vertebrae and is estimated to have grown to a maximum length of between 12.8 and 14.3 metres, is of a comparable size.

The new species has been named Vasuki indicus, after Vasuki, a serpent in Hinduism that is often depicted curled around the neck of the god Shiva. The researchers say it is likely to have been an ambush predator living in either a terrestrial or semi-aquatic environment, such as a marsh or swamp, similar to many of today’s large species of python.

Using data from modern-day snakes that compares the size of their vertebrae with overall length, Datta and Bajpai estimate that V. indicus was between 10.9 and 15.2 metres long. While this is potentially longer than Titanoboa, the researchers emphasise that we don’t have complete skeletons of any Madtsoiid snakes, so it is impossible to know whether their length and vertebrae size would correlate in the same way as living species.

“Caution is always warranted whenever you are extrapolating beyond the available data set,” says Jacob McCartney at Nazareth University in Rochester, New York. “But the vertebrae of this new species are so big that they really are second in size only to those of the Colombian species Titanoboa.”