Giant Rhino-Sized Turtle Found In Spain Is One Of The Largest In Earth's History

A turtle of such Biblical proportions, it's been named after a sea monster.


Rachael Funnell

Social Editor and Staff Writer

clockNov 17 2022, 16:00 UTC
worlds biggest tortoise
The new species' name is taken from a Biblical sea monster and a puzzling enigma. Image credit: ICRA_Arts

An ocean giant that once flapped its way through ancient oceans has been retrieved in Spain, and it’s one of the largest known turtle species ever to exist. The shelled behemoth’s pelvis indicates it could’ve stretched to almost 4 meters (13 feet) in length when it lived between 83.6 to 72.1 million years ago

The largest ever documented marine turtle was Archelon, an absolute unit that went extinct around the end of the Late Cretaceous, approximately 66 million years ago. Now, a new specimen is giving Archelon a run for its money as its pelvis size indicates that it was equally gigantic, making it one of Earth’s largest marine turtles and the biggest ever to swim in Europe’s waters.


The newly discovered species has been named Leviathanochelys aenigmatica. The first part references the Biblical marine beast Leviathan which was actually a sea serpent, but the name alludes to the epic size of L. aenigmatica.

The latter part is taken from the Greek noun αἴνιγμα (“aínigma”) meaning enigma, which is a hat tip to the peculiar anatomical features found on the species’ pelvis and carapace. It was these characteristics that told the study authors they were looking at a new species, and possibly even a new group of turtles.

Leviathanochelys aenigmatica gave even Archelon a run for its money. Image credit: ICRA_Arts
Leviathanochelys aenigmatica gave even Archelon a run for its money. Image credit: ICRA_Arts

The prehistoric giant was retrieved from the Cal Torrades locality in northeastern Spain where it’s thought to have been hiding beneath the surface for around 80 million years. That puts its lifetime back to the Campanian Age, a time when sea level rise saw the ocean reclaim coastal areas while predatory beasts like the spiral-saw-jawed Helicoprion prowled the waters.


The ancient remains include the turtle’s pelvis and parts of its carapace. A unique bony structure on its pelvis indicates that the find represents a new taxon of turtles as this curious feature hasn’t been observed on the remains of other species. The authors suggest its function may have something to do with a unique respiratory anatomy.

Its gargantuan size is an example of convergent evolution as until now the giants of the turtle world existed in North and South America. Evidently, gigantism emerged in multiple turtle lineages from across the globe, resulting in species with colossal shells drifting about on opposite sides of the planet.

Size comparions for the extinct giant turtles Archelon, Leviathanochelys aenigmatica and a human
Height comparion for three turtles and a human. Image credit: (c) IFLScience and Ivan_Sabo/Shutterstock

To date, it was thought that the largest marine turtles to ever sail the oceans, such as the protostegids Archelon and Protostega, were restricted to North America during the latest Cretaceous (Campanian–Maastrichtian),” wrote the authors.


“The discovery of the new, gigantic and bizarre chelonioid Leviathanochelys aenigmatica from the Middle Campanian marine deposits of the Southern Pyrenees, which rivals in size to Archelon, sheds a light on the diversity of marine turtles and on how the phenomenon of gigantism in these groups was also occurring in Europe.”

The study was published in Scientific Reports.

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