Giant Anacondas Blew Up 12 Million Years Ago

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TTwelve million years ago, during the Miocene, South America was covered in a tropical jungle even larger than its current green area, with a few key differences. Warmer temperatures, wetter wetlands, and more abundant food sources made it a paradise for reptiles, and they literally lived large. Nine-foot turtles swam in the rivers while 42-foot caimans strolled along the banks. Now, according to new research published in the Journal of Vertebrate Paleontology, we can add giant anacondas to the list of massive reptiles that inhabited these ancient swamps.

Researchers measured 183 fossilized vertebrae from 32 anaconda specimens discovered in Venezuela and determined that these snakes grew enormous and remained enormous: 13 to 16 feet long, the same size they are today. What’s particularly striking is that giant snakes weren’t even bigger in an era marked by colossal reptiles.

Read more: »The rise and fall of the living fossil»

“This is a surprising result because we expected to find the ancient anacondas measuring seven or eight meters long,” said Andrés Alfonso-Rojas, co-author of the study and a Ph.D. student at the University of Cambridge, said in a statement. “But we have no evidence of a larger snake from the Miocene, when global temperatures were warmer.”

Unfortunately, the other South American giants did not hold up in subsequent eras as well as their serpentine brethren.

“Other species like giant crocodiles and giant turtles have disappeared since the Miocene, probably due to cooling global temperatures and shrinking habitats, but giant anacondas have survived: they are extremely resilient,” added Alfonso-Rojas.

You know what they say: live large, die old, and leave an incredibly massive skeleton.

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Main image: reptiles4all / Shutterstock

• Jake Currie

  Published on December 3, 2025

  Jake Currie is a writer based in Brooklyn, New York.