Prehistoric Giant Turtles Emerge from the Water
Xu Rui
JAIME CHIRINOS
Please envision the scene: 12 million years ago, in the swamps and rivers of northern South America, some giant male turtles that lived here were engaged in an epic battle for mates and territory. The male turtles, with shells 2.4 meters long, had non-ordinary giant horns at the front, used for clashing and grappling, and these horns could even fend off crocodiles that were three times the size of their colossal bodies.
According to *Science*, this depicts a scene from newly discovered fossils in Colombia and Venezuela. This heavy turtle, known as the 'Ground-Text Turtle,' weighed 1100 kilograms. Although it looks like a ferocious predator, careful observation of its huge jaw suggests that it was actually a soft-shelled animal and giant fruit eater.
Although the Ground-Text Turtle was discovered in 1976, it was only in the form of turtle shell fragments. This is the first time that researchers have found horns on its fossil.
Over the past 6 years, Spanish paleontologists Edwin Cadena and his colleagues at the University of Rosario in Venezuela and the Tatacoa Desert in Colombia, along with the discovery of a fragment of the jawbone, have found several complete Ground-Text Turtle fossils, including the first block of jawbone. This is very similar to previous jawbone fossils found in Brazil and Peru (previously classified as other species).
Cadena and his colleagues recently published a paper in *Science Advances* proposing that, based on the matching of the newly discovered jawbone fossils with jawbone fossils from other regions, all the fossil remains should be classified as Ground-Text Turtles. This means that this turtle, which weighs almost as much as a hippopotamus, was once distributed in a large area along the coasts of Brazil, Peru, Colombia, and Venezuela, which was a vast river and wetland system at the time.
The most attractive thing about the new Ground-Text Turtle fossils is that horns were previously not found. Walter Joyce, a paleontologist from the University of Fribourg in Switzerland, said, 'These horns have a long scar on one side, they are very noticeable and very strange.'
Researchers concluded that these horns belonged to the male of the species and they may have used the horns to fight each other. Joyce also thinks so. This view is confirmed by modern land turtles. Male turtles also fight for mates, and they can even flip opponents over. Joyce said that since Ground-Text Turtles lived in swamps and rivers, their fighting styles may be different.
However, little is known about the behavior of Ground-Text Turtles, which are now closely related to sea turtles, living in the jungle midstream of the Amazon River. Joyce lamented, 'And we also don't have Jane Goodall in the sea turtle research community.'
The new jawbone fragments also suggest that Ground-Text Turtles may not be the ferocious predators that were previously thought. These new fossils show that it has a wide, rounded surface on top of its mouth, which can be used to grind, indicating that this animal could break open the shells of soft-shelled animals with its strong jaws. The Ground-Text Turtle's mouth, which is about 30 centimeters wide, could allow it to swallow giant palm fruits and disperse their seeds, just like some sea turtles today.
Cadena said that such a diverse diet may have been the reason for the Ground-Text Turtle's huge size. He added, 'Such a size is an effective defense against predators of the same size, such as 10-meter-long crocodiles, which also lived in the region.' Several Ground-Text Turtle shells have bite marks, and a tooth resembling a crocodile tooth is still embedded in the shell.
Editor: Li Xiaishan
