‘Largest turtle that ever existed’ weighed more than a tonne and had an eight-foot horned shell that it may have used for fighting other turtles 10 million years ago.
Palaeontologists from the University of Zurich have been studying newly found remains of the species, dubbed Stypendemys geographicus.
They say it was the ‘largest turtle of all time’ and would have roamed around a swamp-like environment in what is now Colombia about 10 million years ago.
Researchers say the discovery of the remains of several giant turtles in Brazil, Venezuela and Colombia has helped give a better picture of the massive reptiles.
A giant sea turtle with a horned 8ft long shell may have used it for combat. This is a graphic reconstruction of the giant turtle Stupendemys geographicus: male (front) and female individual (left) swimming in freshwater
They say it was the ‘largest turtle of all time’ and had a shell that weighed more than a tonne, likely used for battling over males to the death over food and females
It had an armoured carapace that could have been used in fights to the death with male rivals over mates or food, the researchers say.
The turtle lived in South America in an area that would have been like a ‘lost world’ of bizarre oversized creatures – including enormous rats and alligators.
The bulk of the remains were found in an ‘animals graveyard’ known as La Venta in the Tatacoa Desert of Colombia.
The giant turtle has a shell 8ft in length but would be much bigger than that when you include the head and legs. The Leatherback turtle has a 5ft 7 shell but can stretch to over 7ft
The bulk of the remains were found in an ‘animals graveyard’ known as La Venta in the Tatacoa Desert of Colombia
It would have weighed more than a tonne and its shell stretched to just under 8 feet – almost twice as large as its closest modern relative the Amazon river turtle.
For comparison, the largest turtle today is the Leatherback sea turtle, it has a shell of about 5ft 7in and a total length of just over 7ft.
While they haven’t confirmed the total length of the Stypendemys including head and legs- it would have been larger than the largest turtle today – by some margin.
It had an armoured carapace that could have been used in fights to the death with male rivals over mates or food, the researchers say
‘The now-extinct animal is the largest land turtle of all time. The remains include the biggest complete turtle shell ever identified,’ said lead author Edwin Cadena.
‘It is twice the size of the largest turtle today, the marine leatherback Dermochelys coriacea.”
The findings, published in the journal Science Advances, significantly expand the known range of Stupendemys to more of what is now South America.
They also indicate it was the lone giant species in the northern Neotropics. It was first identified in 1976 from remains discovered in Venezuela.
Professor Cadena, a palaeontologist at at the University of Rosario in Bogota, said knowledge of these reptilian giants has stalled due to a lack of full specimens.
To uncover more information about the turtle’s prehistoric life, his team conducted detailed anatomical analyses on specimens from 1994 to today.
‘This is a feature that may have served to protect their massive skulls when engaged in combat with other males,’ he said.
The authors also suggest Stupendemys may have achieved such unparalleled size due to the presence of warm, extensive wetland and lake habitats.
“Massive crocodiles may also have influenced the turtle’s evolution, with bite marks on some specimens,’ the authors said.
This included a lone crocodile tooth protruding from a carapace which suggests they ‘needed protection from other lurking giants’.
The findings, published in the journal Science Advances, significantly expand the known range of Stupendemys to more of what is now South America
Colombian paleontologist, Dr Edwin Cadena, taking notes from one of the male specimens of Stupendemys geographicus during a fieldwork season in 2016
When Stupendemys inhabited South America, carnivorous mammals had not yet arrived on the continent, since the Isthmus of Panama was not yet formed and there was no terrestrial connection with Antarctica.
It was isolated, like a giant island. The apex predators were giant crocodiles and alligators, up to 40 feet long.
‘Bite marks and punctured bones on Stupendemys indicate interactions with large caimans that also inhabited the marshy environment,’ Cadena said.
Some extinct South American animals of the time reached giant proportions because of these unique conditions during the Late Miocene.
The phenomenon was unique to the continent. Only here did so many species develop gigantism.