The authors made a modified artistic impression of a madtsoiid snake using

Paleontologists have unearthed fossil remains of an ancient giant snake species — almost the length of a large tour bus — dating back to 47 million years old1, and comparable to the longest snakes that have ever lived on earth.

They found 27 well preserved fossil vertebrae of Vasuki indicus from a lignite mine in India's Gujarat state, and used them to model the estimated actual length of the snake to somewhere between 10.9 to 15.2 metres. The longest known snake at around 13 metres is the extinct Titanoboa that lived 60 million years ago in present day Colombia.

Paleontologists Sunil Bajpai and Debajit Datta at the Indian Institute of Technology in Roorkee say V. Indicus was likely a slow-moving predator that wrapped its body around the prey to squeeze it to death. It evolved in the warm Indian subcontinent and spread to Africa via Europe around 56 to 34 million years ago, they say. V. indicus flourished in forested swamps of the now arid Kutch region.

“The largest of its vertebrae is 11 cm wide,” Datta, the lead author of the study, says. They used data from living snakes and known fossil records as inputs to model its actual size.

V. indicus belonged to the now extinct madtsoiidae snake family from 100 million years ago, a relic of the Late Cretaceous to the Late Pleistocene geological era. It lived across a broad geographical range including Africa, Europe, and India. The reptile is closely related to other large madtsoiid snakes (Madtsoia pisdurensis) from the Late Cretaceous of India and the Late Eocene of North Africa (Gigantophis garstini).

The authors say the snake represents a distinct lineage that originated in India at a temperature of around 28°C about 88 million years ago when the Gondwana supercontinent broke up and the Indian landmass got isolated. “Since this group was dominated by madtsoiids from India and Vasuki was the most primitive ancestor in the family tree, we inferred that this group of snakes originated in India,” Bajpai says.

Roughly 50 million years ago, the Indian subcontinent collided with Asia and land connections formed with north Africa through southern Eurasia, allowing madtsoiid snakes to disperse and evolve. This was most likely how the North African giant madtsoiid Gigantophis garstini originated, according to Bajpai.

“While high temperatures spur the development of large bodies in snakes and other cold-blooded organisms, current temperatures are rising too fast for these snakes to become as massive as they did in the past,” Datta says.