KANAB, Utah (KDVR) — New research released Monday from the Bureau of Land Management in Utah indicates that tyrannosaur dinosaurs may not have been solitary predators, as in the movies, but social carnivores, similar to wolves.
The research is based on a fossil site inside the Grand Staircase-Escalante National Monument called the “Rainbows and Unicorns Quarry“.
The research findings were put together by a team from BLM, Denver Museum of Nature and Science, University of Arkansas, Colby College of Maine and James Cook University in Australia.
U of A associate professor of geosciences Celina Suarez says the new discovery is consistent with how and where the fossils were found on sight.
“This supports our hypothesis that these tyrannosaurs died in this site and were all fossilized together; they all died together, and this information is key to our interpretation that the animals were likely gregarious in their behavior,” Suarez said.
The Rainbows and Unicorns Quarry site was discovered in 2014 by BLM paleontologist Dr. Alan Titus. The BLM said it is the first tyrannosaur mass death site found in the southern United States.
Titus said the research team found that the tyrannosaurs died together during a seasonal flooding event that washed their carcasses into a lake, where they sat, largely undisturbed until the river later churned its way through the bone bed. Part of the Tyrannosauridae family, the Greek meaning behind the Teratophoneus’ name is “monstrous murderer.”
“We used a truly multi-disciplinary approach (physical and chemical evidence) to piece the history of the site together, with the end-result being that the tyrannosaurs died together during a seasonal flooding event,” said Dr. Celina Suarez of the University of Arkansas.
BLM said that in addition to tyrannosaurs, seven species of turtles, multiple fish and ray species, two other kinds of dinosaurs, and a nearly complete skeleton of a juvenile (12-foot-long) alligator have all been discovered on the site.
“The new Utah site adds to the growing body of evidence showing that tyrannosaurs were complex, large predators capable of social behaviors common in many of their living relatives, the birds,” said project contributor, Dr. Joe Sertich, Curator of Dinosaurs at the Denver Museum of Nature & Science. “This discovery should be the tipping point for reconsidering how these top carnivores behaved and hunted across the northern hemisphere during the Cretaceous.”
Based on findings at a site in Alberta, Canada, with over 12 individuals, the idea that tyrannosaurs were social with complex hunting strategies was first formulated by Philip Currie over 20 years ago.
Research will continue at the Rainbows and Unicorns Quarry for the foreseeable future, according to the BLM.
University of Arkansas officials say future research plans for the Rainbows and Unicorns Quarry fossils include additional trace element and isotopic analysis of the tyrannosaur bones, which paleontologists hope will determine with a greater degree of certainty the mystery of Teratophoneus’ social behavior.