Dinosaurs of a feather flocked together, University of Alberta study finds

Bird-like dinosaurs were social creatures and likely flocked together, contrary to the popular image of dinosaurs as solitary creatures, suggests a study at the University of Alberta.

"It changes our perception of the species quite a bit," said Gregory Funston, a PhD student and Vanier scholar at the University of Alberta.

"Until now they were only known from single skeletons," he said. "The idea that these dinosaurs were running around solitary, to have that suddenly change to the idea that there were huge flocks of these things."

The evidence was found in a bone bed in a remote Mongolian desert, first discovered by paleontologists more than a decade ago.

Rare find

Among the ancient collection of skeletons, Funston and his team recently uncovered a group of Avimimus skeletons entwined together.

It's an extremely rare find. 

Funston, who has traveled to Mongolia several times to work on the excavation, said it is common knowledge that modern birds form flocks, but this is the first evidence that their dinosaur ancestors also shared in the behaviour. 

"It's an interesting site. We've found hundreds and hundreds of bones.

"But usually what you find is a single dinosaur skeleton all together as it would have been in life and it's very rare to find deposits like this."

Funston said the remains had time to decompose before they were moved by a large surge of water to create the scattered bone bed.

"This is as if you took a skeleton, put it in a cardboard box, jumbled it around and then spread it out on the ground," Funston said.

"So when you look at the site, you can't recognize any of the individual animals. The bones are all mixed together."

A mysterious meeting 

Funston said that because the bones are scattered, some key evidence has been lost, making it impossible to know for sure what the beaked creatures were up to during that prehistoric meeting.

However, roosting, foraging, mate selection or flocking together for protection from predators are all possible reasons for the gathering.

"This is the first case where we have 18 individuals, and there is no reason why they wouldn't have been together before they were buried. It's a very strong indicator of social behaviour in these animals."

While fossil evidence of dinosaurs living in groups during the Triassic and Jurassic periods exists, it dominates the later Cretaceous period.

Funston said the discovery highlights how dinosaur behaviour may have evolved to become more social over time and provides important clues on the biology and behaviour of bird-like dinosaurs.

And even now, the bone bed may hold more clues.

"These dinosaurs are really helping us learn a lot about Avimimus, and it's helping us set a precedent that we can work off in future studies.

"And we only uncovered a small part of the bone bed. There are probably hundreds of animals in this flock."