KANAB, Utah – The Bureau of Land Management released a new study that indicates fearsome Tyrannosaurus rex traveled in packs and were not lone hunters as previously thought.

The study, released Monday, came from years of work at a fossil site inside Grand Staircase-Escalante National Monument in southern Utah.

BLM paleontologist Dr. Alan Titus discovered the Rainbows and Unicorns Quarry site in 2014.

“We realized right away this site could potentially be used to test the social tyrannosaur idea. Unfortunately, the site’s ancient history is complicated,” Titus said. “With bones appearing to have been exhumed and reburied by the action of a river, the original context with which they lay has been destroyed. However, all has not been lost.”

“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 Dr. Joe Sertich, curator of dinosaurs at the Denver Museum of Nature and Science. “This discovery should be the tipping point for reconsidering how these top carnivores behaved and hunted across the northern hemisphere during the Cretaceous.”

Researchers believe the Tyrannosaurs died during a flood that washed their remains into a lake.

Aside from the 12 Tyrannosaurs, the crew found fossils from other dinosaurs, turtles, and a 12-foot-long Deinosuchus alligator.

The Bureau of Land Management is proud to announce new ground-breaking research regarding the social behavior of Tyrannosaurs! To find out more visit https://t.co/iWPtLzZvwe. pic.twitter.com/wq82eYRruo

— Bureau of Land Management Utah (@BLMUtah) April 19, 2021

Titus called it, “an especially important site that we found in 2014. A one of a kind, the first of its kind from the southern U.S.”

The fossils dated back 76.4 million years.

The news release said researchers will be at the site for years to come.