Tyrannosaur dinosaurs may not have been solitary predators as previously imagined, but looked more like social carnivores such as wolves, according to a new study.
The idea of these “social tyrannosaurs” emerged more than twenty years ago following the discovery of a dozen specimens on the same site, in Alberta (Canada). More recently, in 2011, the discovery of three sets of footprints in British Columbia (still in Canada) by paleontologist Richard McCrea also seemed to point in the same direction. And for good reason, according to the analyzes made on the spot, the three individuals responsible for these traces were running at the same time in the same direction.
However, many scientists have questioned this “gregarious tyrannosaurs” hypothesis, arguing that these animals lack the brains needed to engage in such extensive social interactions. But was it really the case? A new study published in the journal Peerj relaunches the debate today.
Several dead specimens together
In 2014, Bureau of Land Management paleontologist Alan Titus stumbled upon a new site: the Rainbows & Unicorns Quarry. These references to rainbows and unicorns come from the teasing of these colleagues in response to his perpetual excitement over any new discovery. You will find this site in the Grand Staircase-Escalante National Monument, in southern Utah (United States).
That being said, at this site, the paleontologist came across the remains of four, possibly five tyrannosaurs, including a juvenile of about four years (species Teratophoneus curriei).
Based on a geochemical analysis of the bones and surrounding rock, a team from the University of Arkansas recently determined that all of these specimens were dead at the same time and in the same place, victims of a vast flood wiped about 76.4 million years ago. All were buried in fine mud, dug up and then re-buried in a sandbank.
According to Joe Sertich, curator of dinosaurs at the Denver Museum of Nature and Science, “This new site adds to the growing body of evidence showing that tyrannosaurs were large, complex predators capable of social behaviors common to many of their living relatives.”. So maybe we should reconsider how these large carnivores behaved in their day.
Of course, we will need additional evidence to support this hypothesis. After all, Alan Titus admits, it’s just as possible that all of these top predators, loners and competitors, simply gathered around the same carcass to argue over it.