Parrot-like dinosaurs adapted new arms as they migrated

Experts at the University of Edinburgh have identified a previously unknown species of toothless, two-fingered dinosaurs that resembled parrots around 68 million years ago. The research is providing new insight into dinosaurs known as oviraptors, which were thriving at this point in time.

The research was focused on the analysis of remarkably well-preserved skeletons of O. avarsan that were unearthed by the Edinburgh-led team in the Gobi Desert. 

The unusual new species, Oksoko avarsan, had one less finger on each forearm than other closely-related oviraptors, which had three-fingers. According to the researchers, the loss of one finger may have been an adaptation that helped dinosaurs spread during the Late Cretaceous Period.

Along with its two functional digits, O. avarsan grew to be around two meters in length. They were covered in feathers and had a large, toothless beak similar to the type seen in parrots today. 

The discovery that the dinosaurs could evolve forelimb adaptations suggests the animals could alter their diets and lifestyles, which enabled them to diversify and multiply, according to the team.

Across the evolutionary history of oviraptors, the researchers identified the reduction in size, and eventual loss, of the third finger. The experts discovered that the dinosaurs’ arms and hands changed drastically as they migrated into new geographic areas – specifically as they spread throughout North America and the Gobi Desert.

The study revealed that, like many other prehistoric species, O. avarsan was social at a young age. The fossil remains of four young dinosaurs were preserved resting together.

“Oksoko avarsan is interesting because the skeletons are very complete and the way they were preserved resting together shows that juveniles roamed together in groups,” said study lead author Dr. Gregory Funston. “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. 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.”

The study is published in the journal Royal Society Open Science.

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By Chrissy Sexton, Earth.com Staff Writer