Moneycontrol PRO
HomeScienceScientists find Anacondas have stayed giant for 12 million years

Scientists find Anacondas have stayed giant for 12 million years

Fossil analysis reveals anacondas reached giant size 12 million years ago and have remained largely unchanged, offering rare insight into long-term evolutionary stability.

December 03, 2025 / 11:06 IST
Anacondas remained giant for 12 million years (Image: Canva)

Scientists analysed 183 fossilised vertebrae from Venezuela’s ancient river systems. These fossils represent at least 32 individual prehistoric anacondas in total. Researchers used ancestral state reconstruction to estimate snake body lengths. Findings suggest early anacondas already measured 4 to 5 metres.

Size Remained Largely Unchanged 

Modern anacondas are almost the same size as ancient ancestors. For 12 million years, giant anacondas barely altered their body form. This consistency is unusual among large reptiles of the same era. Many other giant species shrank or became extinct over time.

Why Stability Surprised Scientists?

Stable size challenges expectations from changing climate and habitat conditions. Scientists assumed evolutionary pressures would reduce giant reptile dimensions eventually. Anacondas resisted shrinking, highlighting a rare case of evolutionary stasis. Their survival offers insight into long-term adaptation strategies in reptiles.

Habitat Supported Gigantic Growth

Tropical swamps, rivers and wetlands remained warm and water-rich consistently. Aquatic and semi-aquatic lifestyle shielded them from terrestrial evolutionary pressures. Abundant food supply helped maintain large body size across millennia. Environmental stability allowed giant snakes to flourish without drastic evolutionary change.

Significance For Science

This discovery reshapes understanding of reptile evolutionary patterns over millions. It demonstrates species can achieve optimal forms early and remain stable. Anacondas provide a rare example of long-term predator evolutionary consistency. Further research may reveal more about ancient ecosystems and reptile adaptation.

Conservation Implications

Understanding ancient stability can inform modern conservation of riverine habitats. Protecting tropical wetlands ensures survival of large, ecologically important predators. Scientists urge continued study to link fossil data with present biodiversity. Giant snakes remind humans of evolutionary marvels surviving countless millennia.

first published: Dec 3, 2025 11:06 am

Discover the latest Business News, Sensex, and Nifty updates. Obtain Personal Finance insights, tax queries, and expert opinions on Moneycontrol or download the Moneycontrol App to stay updated!

Subscribe to Tech Newsletters

  • On Saturdays

    Find the best of Al News in one place, specially curated for you every weekend.

  • Daily-Weekdays

    Stay on top of the latest tech trends and biggest startup news.

Advisory Alert: It has come to our attention that certain individuals are representing themselves as affiliates of Moneycontrol and soliciting funds on the false promise of assured returns on their investments. We wish to reiterate that Moneycontrol does not solicit funds from investors and neither does it promise any assured returns. In case you are approached by anyone making such claims, please write to us at grievanceofficer@nw18.com or call on 02268882347