New Small-Bodied Ankylosaur Species Unearthed in Argentina

A new genus and species of nodosaurid ankylosaur has been identified from fossils found in Patagonia, Argentina.

Life reconstruction of Patagopelta cristata. Image credit: Gabriel Díaz Yalten.

Patagopelta cristata roamed Earth during the Late Cretaceous epoch, between 75 and 70 million years ago.

The ancient beast belonged to Ankylosauria, a group of quadrupedal, herbivorous armored dinosaurs in the order Ornithischia.

“The fossil record of ankylosaurs is abundant for the Cretaceous of the northern hemisphere, but is very poor in the southern hemisphere, with a few species known from Australia, Chile, Antarctica and Morocco,” said Facundo Riguetti, a Ph.D. student at the Universidad Maimónides and CONICET, and his colleagues.

From the size of its bones, the paleontologists estimate Patagopelta cristata was about 2 m (6.6 feet) long.

“The 2-m body length estimated for Patagopelta cristata is very small for an ankylosaur, comparable with the dwarf nodosaurid Struthiosaurus,” they noted.

The fossilized material of the new dinosaur species was found in the Allen Formation in Salitral Moreno in the Argentinian province of Río Negro.

The specimens included vertebra, a tooth, a partial femur, and osteoderms — bones embedded within the skin.

“The best preserved element from Patagopelta cristata is a femur,” the researchers said.

“Another important and distinctive element is a portion of the neck armor, which has particular spines and crests.”

According to the authors, Patagopelta cristata was a type of nodosaurid ankylosaur.

“We recovered Patagopelta cristata within Nodosaurinae, related to nodosaurids from the ‘mid’-Cretaceous of North America, contrasting the previous topologies that related this material with Panoplosaurini (Late Cretaceous North American nodosaurids),” they said.

“These results support a paleobiogeographical context in which the nodosaurids from Salitral Moreno, Argentina, are part of the allochthonous fauna that migrated into South America during the Late Campanian as part of the First American Biotic Interchange.”

Source: sci.news