Details of the discovery were published in 2024 in Scientific Reports. The fossils were excavated in the western Indian state of Gujarat, where researchers estimate that Vasuki measured between 10.9 and 15.2 meters (36 to 50 feet). Its exact size remains uncertain because only part of its skeleton has been recovered.

Even so, the snake’s enormous size and unusual evolutionary history offer a glimpse into a time when giant reptiles lived in the warm, tropical landscapes of ancient India.

Giant snake fossil discovered in India

Paleontologists Debasit Dutta and Sunil Bajpayee of the Indian Institute of Technology Roorkee identified the species from fossils recovered at the Panandhro lignite mine in Kutch, Gujarat. The remains date to the middle Eocene, about 47 million years ago, when Earth’s climate was considerably warmer than it is today.

The researchers examined 27 fossilized vertebrae, the bones that formed the snake’s backbone. Many of the vertebrae were well preserved, and some remained connected in their original arrangement. Their size and condition suggest that they belonged to a fully grown animal.

The species was named Vasuki Indicus after Vasuki, the mythical serpent associated with the Hindu god Shiva. Vasuki is traditionally depicted wrapped around Shiva’s neck, while the species name refers to India, where the fossil was found.

How big was Vasuki Indicus?

Although scientists did not recover a complete skeleton, the preserved vertebrae provide important clues about the snake’s enormous body.

The individual vertebrae ranged from 37.5 to 62.7 millimeters (1.48 to 2.47 inches) in length and from 62.4 to 111.4 millimeters (2.46 to 4.39 inches) in width. Their unusually broad shape suggests that Vasuki had a thick, cylindrical body capable of supporting substantial weight.

To estimate the animal’s total length, researchers compared the fossilized vertebrae with the vertebrae of living snakes whose body lengths are known. Two methods produced different estimates: one suggested a length of 10.9 to 12.2 meters (36 to 40 feet), while the other produced a range of 14.5 to 15.2 meters (48 to 50 feet).

These estimates place Vasuki among the largest snakes ever discovered. Its possible maximum length is greater than the estimated 13-meter (43-foot) length of Titanoboa, a giant snake that lived in what is now Colombia about 60 million years ago.

However, researchers caution that the comparison is not definitive. Reconstructing the size of an extinct animal from an incomplete skeleton involves considerable uncertainty, and different methods can produce significantly different results. It remains unclear whether Vasuki truly exceeded Titanoboa in length.

A giant predator that may have hunted by ambush

Despite its intimidating size, Vasuki was probably not a particularly fast or agile hunter.

Researchers suggest that its large body and unusual spinal structure may have favored relatively slow movement. Instead of actively chasing prey, the snake may have relied on ambush tactics, remaining hidden until another animal came within striking range.

Its hunting strategy may have resembled that of modern anacondas and large pythons, which overpower prey through constriction. These snakes use their powerful bodies to tighten around captured animals, disrupting circulation until the prey dies.

The exact diet and behavior of Vasuki cannot be determined from the available fossils. Nevertheless, its anatomy and size are consistent with a large ambush predator.

The snake may not have lived exclusively in water. Instead, it could have spent much of its time on land or in shallow swamp environments. Wetlands and swamps surrounded the fossil site during the Eocene and may have provided suitable habitat for a massive snake.

How ancient India’s warm climate may have supported giant snakes

The discovery raises broader questions about why some prehistoric snakes grew far larger than most species living today.

During the middle Eocene, the region where Vasuki lived experienced tropical conditions, with average temperatures estimated at about 28 degrees Celsius (82 degrees Fahrenheit).

Snakes are ectothermic, meaning they rely heavily on external heat sources to regulate their body temperature. Warmer environments can support activity, digestion and growth in large reptiles. This may help explain why exceptionally large snakes appeared during periods of global warmth.

Temperature alone, however, does not determine how large a snake can become. Food availability, habitat, evolutionary history and other environmental factors also influence body size.

An extinct lineage of giant snakes that spread across continents

Beyond its unusual size, Vasuki provides evidence of an ancient branch in snake evolution.

The species belonged to the Madtsoiidae, an extinct family of snakes that survived for roughly 100 million years, from the Late Cretaceous to the Late Pleistocene. Members of this group lived across regions that included India, Africa, Europe, South America and Australia.

Unlike modern anacondas and pythons, Vasuki represented a separate evolutionary lineage within this long-extinct family.

Researchers identified close relatives including Madtsoia pisdurensis, an ancient Indian fossil snake, and Gigantophis garstini, another large prehistoric snake known from North Africa.

These relationships suggest that the giant madtsoiid lineage may have originated in the Indian subcontinent before spreading to other parts of the world.

India’s geographic connections changed as the subcontinent moved north and collided with Asia about 50 million years ago. The snakes may have dispersed through southern Eurasia, including southern Europe, and eventually into Africa during the Eocene, which lasted from about 56 to 34 million years ago.

Later fossil discoveries reveal a diverse ancient snake community

A study published in 2025 added further context to the discovery of Vasuki.

In that research, Dutta and Bajpayee described additional snake fossils from Eocene deposits in western India. The fossils reveal a surprisingly diverse community of ancient reptiles, including aquatic snakes, another large member of the madtsoiid family and other extinct snake groups.

Among the discoveries was Pterosphenus ranensis, an ancient aquatic snake species that may help scientists better understand how these reptiles evolved and spread.

Researchers also identified another madtsoiid snake that may have shared the wetland environment with Vasuki. This suggests that the giant predator was part of a broader snake community with a range of ecological roles, rather than an isolated evolutionary oddity.

Fossil evidence indicates that some of these snakes lived in tidal environments, while others inhabited wetlands and swamps. Together, the discoveries provide a more detailed picture of the complex ecosystem that existed in India tens of millions of years ago.

What ancient anacondas reveal about giant snakes

Another study published in 2025 in the Journal of Vertebrate Paleontology provided additional evidence about the evolution of giant snakes.

Researchers examining fossilized anaconda vertebrae from Venezuela found that these snakes had already evolved large bodies by about 12.4 million years ago. Ancient anacondas are estimated to have reached approximately 5.2 meters (17 feet) in length, comparable to many modern anacondas.

The findings suggest that anacondas maintained their impressive size for millions of years despite changes in climate and ecosystems. They also show that prehistoric snakes did not necessarily become larger simply because Earth was warmer.

Anacondas and Vasuki belonged to different evolutionary lineages, but the comparison helps scientists understand how separate groups of snakes evolved giant bodies and adapted to their environments.

The mystery of Vasuki Indicus remains

The story of Vasuki Indicus is still incomplete. Its exact size, appearance and hunting behavior remain uncertain, but the fossil evidence confirms that it was an extraordinary example of prehistoric gigantism.

This ancient snake, together with later discoveries from the same region, is helping scientists reconstruct a largely forgotten world in which giant snakes lived among the tropical wetlands of ancient India.