Giant 'monster dragon' revealed, 90 million year old relative of snake

A completely new species of sea monster has just been found in Mexico, with a body up to 5.2 m long, a long snout like a crocodile and is an extremely fearsome predator .

According to research led by paleontologist Herto Rivea-Sylva from the Desert Museum (Mexico), the new species, which they named Yaguarasaurus regiomontanus , was a member of the mosasaur family.

A group of large, ferocious marine reptiles that lived at the same time as the dinosaurs. Many mosasaurs were at the top of the food chain in the seas they roamed. The newly discovered one may have been one of those .

Portrait of the mosasaur monster Yaguarasaurus regiomontanus - (Graphic: DESERT MUSEUM).

The creature was recently unearthed as a fossil in a layered limestone layer in Mexico's Agua Nueva Formation, which is up to 90 million years old, dating back to the Cretaceous period.

This famous layer of rock has revealed many exquisitely preserved species of fish and marine reptiles, as it formed in an open shelf environment under anoxic conditions.

Among them, Yaguarasaurus regiomontanus is one of the largest, most complete and most fearsome specimens.

An exquisite fossil fragment from the monster - (Photo: DESERT MUSEUM).

According to Sci-News , analysis results show that it was up to 5.2 meters long when alive, making it one of the earliest known large mosasaurs.

Like other mosasaurs found around the world, it was a formidable predator and larger than other marine creatures of its time. A total of 40 mosasaurs have ever been recorded, with the largest specimen measuring 12 meters in length.

The closest living relatives of mosasaurs are snakes.

The features of this Yaguarasaurus regiomontanus indicate that it belonged to a genus of mosasaurs called Plioplatecarpus, and was a large one compared to others in its genus.

The graphic recreation of the creature shows a dragon-like creature with fins similar to those of contemporary marine reptiles, a head with a long, crocodile-like snout and a terrifying snake tongue.

The creature is an important discovery, the authors say, because it emerged after an extinction event in the Cretaceous period.

Unfortunately, like all other dinosaurs, pterosaurs, ichthyosaurs and mosasaurs, it became extinct after the giant Chicxulub asteroid hit Earth 66 million years ago.

Research on this new "monster dragon" species has just been published in the scientific journal Journal of South American Earth Sciences.