Gigantic turtle from the dinosaur era was almost 4 metres long

Leviathanochelys aenigmatica, which lived sometime between 72.1 million and 83.6 million years ago, is one of the largest marine turtles ever found

By Jason Arunn Murugesu

An ancient species of turtle whose remains have been discovered in Spain is the largest marine turtle ever found in Europe.

The turtle, which has been named Leviathanochelys aenigmatica, was up to 3.74 metres long. It lived sometime between 72.1 million and 83.6 million years ago, around the same time as dinosaurs such as Velociraptor.

Fragments of the fossil were first found by a hiker in 2016 in Coll de Nargó, a village in the Catalonia region. The remains were dug up and collected by local government and museum officials.

In 2021, Àngel Luján at the Autonomous University of Barcelona and his colleagues conducted more excavations of the area and discovered that the fossil actually belonged to a new species of turtle. During this excavation, the team realised that the turtle’s 90-centimetre-wide pelvis had two bone bulges on its front, unlike any other turtle pelvises previously described.

The turtle is the second-largest marine turtle ever discovered and the largest to have been found in Europe.

The biggest marine turtle ever discovered, Archelon, was found in North America and is estimated to have had a body length of 4.6 metres.

“Our discovery also indicates that gigantic marine turtles evolved several times in distinctive families,” says Luján.

The turtle probably had a similar diet to other marine turtles, such as sponges, algae and barnacles, he says.

It is unclear exactly why these turtles grew so big, but Martin Sander at the University of Bonn in Germany suggests that giant male turtles may have had better reproductive success. “Giant turtles probably spread all over the world like leatherback turtles today,” he says.

Luján says he expects there to be many more discoveries of ancient giant turtles in Europe. He says there are many fragmentary remains of such turtles in countries like Italy and the Czech Republic, but they aren’t as intact as the turtle his team discovered.

“We are optimistic and we believe that it is possible to find more giant turtle species in Europe,” he says.

The finding also hints at the possibility of finding more giant turtles in North Africa. “Southern Europe and North Africa shared several faunas, both marine and terrestrial, during the Late Cretaceous, between 80 and 66 million years ago,” says Luján. “Because of that, it would be not surprising to discover new gigantic marine turtles in these regions.”

Journal reference: Scientific Reports, DOI: 10.1038/s41598-022-22619-w