Fossils reveal anaconda snakes have been huge for millions of years

If you aren't a big fan of snakes, then this story might not be for you - as it is all about one of the largest reptiles in the world.

Anacoda snakes, found in tropical South America, are among the heaviest and longest snakes that live on Earth.

Scientists have now discovered that they've been huge for millions of years.

A new study of ancient fossils found these creatures grew to more than a whopping 5 metres in length.

The study was carried out by scientists from Cambridge University in the UK.

The team took a closer look at 183 anaconda fossils, dating back 12.4 million years, that had been discovered in the South American country of Venezuela.

They measured the fossils and also looked at fossil data from other sites around the continent.

This allowed them to calculate that ancient anacondas would have been four to five metres long.

What surprised scientists is that this matches the size of anacondas that exist today.

Many animal species that lived that long ago, in the period known as the 'Middle to Upper Miocene', were much bigger than their modern relatives.

This was due to a number of factors including warmer global temperatures, extensive wetlands and plenty of food.

Lead author Andrés Alfonso-Rojas, from the University of Cambridge, explained: "By measuring the fossils we found that anacondas evolved a large body size shortly after they appeared in tropical South America around 12.4 million years ago, and their size hasn't changed since."

He added: "This is a surprising result because we expected to find the ancient anacondas were seven or eight metres long.

"But we don't have any evidence of a larger snake from the Miocene when global temperatures were warmer."

1. Anacondas are semiaquatic snakes - meaning they live both on land and in water.

2. These non-venomous reptiles live near rivers and swamps and feeds on fish, birds, and mammals.

3. They are found in several countries across South America, mainly in the tropical rainforests of the Amazon.

4. The anaconda is considered to be the biggest snake due to its sheer bulk - and females are often larger than males.

5. The largest anaconda measured was almost 8.5m long. Scientists estimate that it weighed over 226kg.