Multiple skeletons of the Oksoko avarsan, a feathered omnivorous dinosaur that grew to 2 meters in length, were dug up in the Gobi Desert in Mongolia by researchers from the University of Edinburgh, according to a news statement published Tuesday.
It had a large, toothless beak like modern-day parrots and just two digits on each forearm — one less than its close relatives.
It’s the first time scientists have seen evidence of digit loss among oviraptors, a family of three-fingered dinosaurs.
Evolving to have fewer digits suggests they could also “alter their diets and lifestyles, and enabled them to diversify and multiply,” according to the statement.
The “very complete” juvenile skeletons were found resting together, showing that young Oksoko avarsan roamed in groups, said paleontologist Gregory Funston, a post-doctoral researcher at the University of Edinburgh who led the study.
“But more importantly, its two-fingered hand prompted us to look at the way the hand and forelimb changed throughout the evolution of oviraptors — which hadn’t been studied before,” Funston said in a statement.
“This revealed some unexpected trends that are a key piece in the puzzle of why oviraptors were so diverse before the extinction that killed the dinosaurs.”
Oviraptors’ arms and hands evolved rapidly as they migrated to new areas in what is now North America and the Gobi Desert, the team found.
The study published Tuesday in the journal Royal Society Open Science.
It was also “the first largely complete skeleton I think anyone has found of these guys,” she said.
Anzu wyliei was a 600-pound cross between an ostrich and a velociraptor. It had a bird-like beak and apparent feathers, with a large crest atop its skull, and munched on vegetation, small animals and perhaps eggs.