What Is the Largest Snake That Ever Existed?

Some snakes alive today can grow to enormous sizes. There are tales of some large snakes, such as the anaconda or reticulated python, growing to 20 to 30 feet.

Millions of years ago, however, an even bigger one slithered around the Earth. The Titanoboa—the largest known snake to ever exist—was as long as a school bus, growing to an estimated 50 feet long and 3 feet wide.

The species was discovered in 2009 by a multi-organizational team of scientists at the Cerrejon coal mine in Colombia. Jonathan Bloch, a curator in vertebrate paleontology at the Florida Museum of Natural History, who co-led the expedition, estimates that if the beast would have slithered past you, its body would have reached as high as your waist.

For years before the discovery, scientists had debated about how big snakes grew—the general consensus was that it was no larger than 40 feet.

The Titanoboa was also the biggest known predator to roam the planet between the end of the dinosaurs, 65 million years ago, and the time of the Megalodon—a giant shark species that grew up to 58 feet long and lived around 20 million years ago. The Titanoboa would have ruled the land just 6 million years after the time of the Tyrannosaurus rex.

Carlos Jaramillo, a staff scientist at the Smithsonian Tropical Research Institute, co-organized the team that made the gigantic discovery.

"So far no larger [snake] has been found," Jaramillo told Newsweek. "Cerrejon is one of the largest open-pit coal mines in the world and the coal was produced by the earliest tropical rainforest. Fossils of Titanoboa were found along many other fossils including leaves, fruits, seeds, pollen, and other vertebrates including large crocodiles and turtles."

Scientists soon realized, after sifting through many fossils of already known species, that some were unrecognizable. After analyzing these bones, they realized it was a new species altogether.

Scientists didn't believe they were snake bones at first, due to the huge size. But after more research they realized the fossils belonged to the biggest snake that ever lived.

"It could reach 26 inches wide, a width that could double after eating," Jaramillo said. "Its weight could also reach one ton." This is about the weight of a car today.

The predator would have eaten only meat, and its diet probably included the likes of alligators, and crocodiles. But fossils actually indicate that its favorite food was probably turtles.

"We have seen marks of Titanoboa teeth in the carapace of fossilized turtles in Cerrejon," Jaramillo said.

Why Was It So Large?

"Its large size could be possible due to a much warmer temperature compared to today," Jaramillo said.

The sheer size of the animal indicated to scientists that the climate 65 million years ago looked a lot different to how it is today.

Snakes, along with other cold-blooded animals, develop in size depending on the temperature of where they live. And it seemed that this rainforest was a lot warmer in temperature than even some of the hottest parts of the world today. The warmer the climate, the bigger the snake.

"[From this we know that] Cerrejon was a very productive tropical rainforest living at a temperature about 10 degrees warmer than today," Jaramillo said. "We found many specimens of Titanoboa, and the size ranges from 36 to 50 feet long."

Scientists aren't certain when the snake died out or why.

"Still it is not well known," Jaramillo said. "We know it is in the Paleocene, 60 to 57 million years ago, and we think that went extinct at some point in the latest Paleocene or the early Eocene, around 57 to 53 million years ago."

But the Titanoboa's descendants—boas and anacondas—still live among us today. Thankfully, they do not grow to the size of a bus.

Correction 01/16/23 2:21 a.m ET: This article was corrected to say the Titanoboa's descendants still live among us today.