Four meters long, weighing several tons: So far, fossil remains of such gigantic sea turtles are only known from North America. But now such a giant is also being discovered in Europe, which with its 3.7 meters can definitely compete with those from America.
Around 80 million years ago, giant turtles roamed European seas. This is confirmed by the fossil of an estimated 3.7 meter long sea turtle that scientists found in Spain. It is the largest sea turtle discovered in Europe to date and one of the largest in the world, write the researchers in the journal “Scientific Reports”.
The largest sea turtles known to date lived in North America during the Cretaceous Period, such as those of the genus Archelon. Archelon ischyrus reached a length of 4.6 meters and weighed more than three tons. In Europe, the largest specimens only reached a length of about 1.5 meters. The species Leviathanochely aenigmatica, which has now been discovered in the southern Pyrenees, could compete with the huge sea turtles of North America, which weigh several tons, writes the team led by Oscar Castillo-Visa from the University Autonoma de Barcelona.
The remains of the giant were excavated between 2016 and 2021. Part of the back armor and large parts of the pelvic girdle have been preserved. According to the datings, the animal lived about 83.6 to 72.1 million years ago. The researchers derived his height from the size of his pelvis. The width of the basin was just under 89 centimeters over that of Archelon (81 centimeters), the length only 14 percent below.
The finding shows that gigantism evolved independently in different species over time, the scientists write. It is unclear which evolutionary processes exactly favored the development of the giant. In sea turtles that are still alive, body size is related to several environmental factors, such as hunting pressure – i.e. the presence of potential predators – or temperature.
What is striking about L. aenigmatica is a piece of bone protruding from the pelvis, which is not known from other sea turtles. It’s probably related to the respiratory system.