Scientists discover rare two-clawed dinosaur in Mongolia

Scientists have discovered a new species of dinosaur in Mongolia’s Gobi Desert. Called Duonychus tsogtbaatari, the dinosaur has two foot-long clawed fingers on each hand, one fewer than its fellow therizinosauria.

Duonychus, which means two claws in Greek, stood about 10 feet tall and weighed roughly 570 pounds, and belonged to the group of dinosaurs called therizinosaurs, which were characterized by an odd set of traits: huge claws believed to have been used to shear leaves off trees, leaf-shaped teeth, backward-facing hip bones, a long neck ending in a small head, and covered in down and quill-like feathers.

They lived in Asia and North America during the Cretaceous Period, 145 million to 66 million years ago.

Despite having only two claws, the researchers, who described the specimen in a study published Tuesday in the journal iScience, said Duonychus was an “effective grasper” that could reach branches or swaths of vegetation up to nearly 5 inches in diameter.

NBC News has reached out to the research team for comment.

The specimen was excavated in 2012 by researchers from the Mongolian Academy of Sciences’ Institute of Paleontology from the Gobi Desert’s Bayanshiree Formation, which dates back 90 million years and is known for its exceptional diversity of therizinosaurs.

The fossil was a partial skeleton without a skull and legs, but the hands were “exceptionally preserved,” according to the study. The Duonychus individual was not fully mature, and its claws measured about a foot long.

Though therizinosaurs were part of the theropod group, which included meat-eaters like tyrannosaurus and spinosaurus, they mainly ate leaves from large shrubs and trees.

It’s a “great new discovery, and the two claws is interesting,” said Michael Benton, professor of vertebrate palaeontology at the University of Bristol in the U.K., who was not involved in the study.

Dinosaurs used to have five fingers, just like human beings, but they quickly lost two over time, with most dinosaurs having three fingers, Benton told NBC News Wednesday in an email.

“So, to go down to two was unusual,” he said.

The number of digits doesn’t matter when it comes to hooking and pulling, Benton said, adding that the third finger may have been an “encumbrance” due to its short length.

“It shows dinosaurs were amazingly various and diversified in their shapes and functions,” Benton said.

Fossil records of therizinosauria are “notably abundant” in Cretaceous deposits across eastern Asia, particularly in Mongolia and China, according to the study.

The United Nations Educational, Scientific and Cultural Organization (UNESCO) called the Mongolian Gobi Desert the world’s “largest dinosaur fossil reservoir.”