Paleontologists Find Biggest Pterosaur Species Ever Unearthed in South America

The ancient fossils with wingspans the size of school buses are estimated to be 86 million years old

An image of a reconstruction of the pterosaur unveiled at the Museum of Dinosaurs in the National University of Cuyo in Mendoza
Thanatosdrakon amaru flew around the planet for 20 million years before the Cretaceous-Paleogene extinction event wiped out the dinosaurs. National University of Cuyo

Scientists in Argentina have excavated the largest flying reptile species ever unearthed in South America. The two giant specimens, dubbed Thanatosdrakon amaru or "dragon of death," are part of the Azhdarchidae family of pterosaurs that ruled the skies during the late Cretaceous period, 66 to 146 million years ago, reports Jennifer Nalewicki for Live Science. The fossils were found in the Plottier Formation in the province of Mendoza in central Argentina. Details on the flying reptiles will be published in the September 2022 issue of Cretaceous Research.

Thanatosdrakon amaru is thought to predate birds as the first creature with wings to hunt for prey from the air. They flew around on the planet for 20 million years before the Cretaceous-Paleogene extinction event wiped them out, reports Earth.com's Andrei Ionescu. Despite being cold-blooded predators, scientists have placed pterosaurs in the same category as birds because of their ability to fly, reports USA Today's, Scott Gleeson. 

The fossils were found during construction work for a civil project 500 miles outside of Mendoza's capital city, Live Science reports. Paleontologists were supervising the construction dig when fragments of bone were uncovered. The area is known for other fascinating discoveries, such as Notocolossus, a genus of titanosaurian sauropod that is one of the most enormous dinosaurs in the world. It was found in 2016.

The recently discovered pterosaur’s name, Amaru, is a Quechuan word that means “flying serpent,” and refers to the two-headed Incan deity that lives at the bottom of rivers and lakes, reports Abe Asher for the Independent. Thanatosdrakon combines two Greek words, thanatos, meaning “death,” and drakon, which means “dragon.”

One fossilized specimen had a 23-foot wingspan, while the other specimen had a 30-foot wingspan. Researchers suspect that both colossal reptiles may have died simultaneously. One of the pterosaurs was a juvenile, but the team could not confirm if the specimens had a familial relationship, per Live Science. The fossils were in different states of preservation, with some bones intact while others were fragmented pieces. However, enough well-preserved bones were found that the team could identify them as a new species. Pterosaur remains are often fragile, and finding them in workable shape is rare.

"From the beginning, two facts caught our attention: The first was the size of the remains and their preservation in three dimensions, an unusual condition in this group of vertebrates; the second was the amount of remains found at the site since large-giant pterosaurs are only known from fragmentary remains (with some exceptions)," says study lead author, Leonardo D. Ortiz David, to Live Science.

Images of the recently reconstructed pterosaur were unveiled at the Museum of Dinosaurs in the National University of Cuyo in Mendoza and circulated on social media, bringing more attention to the study. The fossils currently reside in the Laboratory and Museum of Dinosaurs in Mendoza, per the Independent.