According to new research published in Scientific Reports, a new species of ancient turtle unearthed in Spain may have been one of the largest marine turtles to have ever lived.

With a body length of up to 3.74 meters, it is the biggest marine turtle ever found in Europe.

Towards the end of the Cretaceous epoch, the seas surrounding the North American continent were home to the largest known marine turtles, such as the old extinct genus Archelon, which reached lengths of 4.6 meters and weights of up to 3.2 tonnes.

In comparison, neither a living nor extinct European sea turtle has ever had a shell longer than 1.5 meters.

The remains of a new sea turtle specimen, which they refer to as Leviathanochelys aenigmatica, were discovered in the Cal Torrades locale, in northeastern Spain, and they were described by Angel H. Luján, Albert Sellés, and colleagues.

The remains, which were unearthed between 2016 and 2021, consist of a shattered but nearly entire pelvis and fragments of the upper shell (carapace). They date to the Campanian Period, which lasted from 83.6 to 71.2 million years ago.

The specimen has an unique bone protrusion that extends forward from the pelvic front.

This trait distinguishes Leviathanochelys from other sea turtles and suggests that it belongs to a new taxon (group) of prehistoric marine turtles.

The authors speculate that this protrusion may have been related to the respiratory system.

The authors estimate that Leviathanochelys may have grown as much as 3.74 meters in body length based on the size of the pelvis.

They calculate that Leviathanochelys’ pelvis had a maximum width of 88.9 centimeters, which is somewhat greater than the largest estimations for Archelon’s most well-known specimen (81.0 cm wide).

Estimates placed the pelvis’ front-to-back length at 39.5 cm, making it a little shorter than Archelon’s (46.0 cm long).

Leviathanochelys is now the largest marine turtle ever found in Europe and among the largest ever found globally.

According to the scientists, these results show that gigantism in marine turtles evolved separately in various lineages in both North America and Europe.

Source: 10.1038/s41598-022-22619-w

Image Credit: Mario Tama/Getty Images