In this photo provided by the Bureau of Land Management, researchers prepare fossils to be airlifted from the Rainbows and Unicorns Quarry on Grand Staircase-Escalante National Monument to the Paria River District paleontology lab in Kanab, Utah, on Sept. 4, 2018. Ferocious tyrannosaur dinosaurs may not have been solitary predators as long envisioned, but more like social carnivores such as wolves, new research unveiled Monday, April 19, 2021, found. (Dr. Alan Titus/Bureau of Land Management via AP)

In this photo provided by the Bureau of Land Management, researchers prepare fossils to be airlifted from the Rainbows and Unicorns Quarry on Grand Staircase-Escalante National Monument to the Paria River District paleontology lab in Kanab, Utah, on Sept. 4, 2018. Ferocious tyrannosaur dinosaurs may not have been solitary predators as long envisioned, but more like social carnivores such as wolves, new research unveiled Monday, April 19, 2021, found. (Dr. Alan Titus/Bureau of Land Management via AP)

Mass fossil site may prove tyrannosaurs lived in packs

A team of researchers determined that the dinosaurs died and were buried in the same place

Ferocious tyrannosaur dinosaurs may not have been solitary predators as long envisioned, but more like social carnivores such as wolves, new research unveiled Monday found.

Paleontologists developed the theory while studying a mass tyrannosaur death site found seven years ago in the Grand Staircase-Escalante National Monument in southern Utah, one of two monuments that the Biden administration is considering restoring to their full size after former President Donald Trump shrunk them.

Using geochemical analysis of the bones and rock, a team of researchers with the University of Arkansas determined that the dinosaurs died and were buried in the same place and were not the result of fossils washing in from multiple areas.

The new Utah site is the third mass tyrannosaur grave site that’s been discovered in North America — bolstering a theory first developed 20 years ago that they lived in packs. However, more research needs to be done to make that argument, said Kristi Curry Rogers, a biology professor at Macalester College who wasn’t involved in the research but reviewed the finding Monday.

“It is a little tougher to be so sure that these data mean that these tyrannosaurs lived together in the good times,” Rogers said. “It’s possible that these animals may have lived in the same vicinity as one another without travelling together in a social group, and just came together around dwindling resources as times got tougher.”

In 2014, Bureau of Land Management paleontologist Alan Titus discovered the site, which was later named the Rainbows and Unicorns quarry because of the vast array of fossils contained inside. Excavation has been ongoing since the site’s discovery because of the size of the area and volume of bones.

“I consider this a once-in-a-lifetime discovery for myself,” Titus told reporters during a virtual news conference. “I probably won’t find another site this exciting and scientifically significant during my career.”

The social tyrannosaurs theory began over 20 years ago when more than a dozen tyrannosaurs were found at a site in Alberta, Canada. Another mass death site in Montana again raised the possibility of social tyrannosaurs. Many scientists questioned the theory, arguing that the dinosaurs didn’t have the brainpower to engage in sophisticated social interaction, Titus said.

“Going that next step to understand behaviour and how animals behave requires really amazing evidence,” Joseph Sertich, curator of dinosaurs at the Denver Museum of Nature & Science, said at the news conference. “I think that this site, the spectacular collection of tyrannosaurs but also the other assembled pieces of evidence … pushes us to the point where we can show some evidence for behaviour.”

In addition to the tyrannosaurs, researchers have also found seven species of turtles, multiple fish and ray species, two other kinds of dinosaurs and a nearly complete skeleton of a juvenile Deinosuchus alligator. These other animals do not appear to have all died together.

Paleontology groups have been among those pushing the federal government to restore the Bears Ears National Monument and Grand Staircase-Escalante to their original sizes to protect the region’s rich paleontological and archaeological record.

Interior Secretary Deb Haaland visited southern Utah earlier this month as she prepared to submit recommendations on whether to reverse Trump’s decision to downsize the monuments. Titus said he showed Haaland some of the fossils at his lab during her visit and said she “appreciated getting to see the material.”

“The (Bureau of Land Management) is protecting these fossils as national treasures.” Titus said. “They’re part of the story of how North America came to be and how ultimately we came to be.”

___

Eppolito is a corps member for the Associated Press/Report for America Statehouse News Initiative. Report for America is a non-profit national service program that places journalists in local newsrooms to report on undercovered issues.

Sophia Eppolito, The Associated Press


Like us on Facebook and follow us on Twitter.

Wildlife

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

Red dot shows location where fisherman was rescued by boater on Friday, May 7, 2021. Other fisher still missing presumed drowned after boat swamped on Fraser River near Vedder/Sumas confluence. Rescued man swam to shore after boat sank, while friend is still classified as missing as of May 10. (City of Chilliwack map)
Fisherman still missing after boat flipped on the Fraser River

One man made it out, other still missing, after anchor got snagged in the Fraser near Chilliwack

Graduating goalie Mathieu Caron stops Prince George forward Nick Rheaume in Sunday’s season finale at the Chilliwack Coliseum. (Darren Francis photo)
Chilliwack Chiefs say goodbye to departing vets in pod season finale

Longtime goalie Mathieu Caron and captain Kyle Penney are among the players aging out of the BCHL

Kent-Harrison Search and Rescue workers and emergency personnel set up a command centre on Friday evening. It took KHSAR to find a lost hiker who veered off-course near Campbell Lake west of Harrison Hot Springs, finding them about 380 metres off-trai and escorted them safely to the trailhead. (Photo/Kent-Harrison Search and Rescue)
Kent-Harrison Search and Rescue guides lost hiker home

Hiker ended up almost 400 metres off-course as darkness fell on May 7

Joan Septembre went for a weekend hike at Lindeman Lake, parking next to a vehicle that had two windows smashed in. (submitted photo)
Thieves active at Lindeman Lake and other parking spots along Chilliwack Lake Road

The hiking community is lamenting an uptick in car theft and vandalism as the weather gets nicer

Coho smolts. (Tanis Grower photo)
OPINION: A giant, invisible problem for Fraser salmon and how to fix it

‘Successful examples of salmon-friendly flood control can already be found throughout the Lower Mainland’

A bullet hole is seen in the windshield of an RCMP vehicle approximately 4 km from Vancouver International Airport after a one person was killed during a shooting outside the international departures terminal at the airport, in Richmond, B.C., Sunday, May 9, 2021. THE CANADIAN PRESS/Darryl Dyck
Homicide team IDs man in fatal YVR shooting as police grapple with spate of gang violence

Man, 20, charged in separate fatal shooting Burnaby over the weekend

The Canadian Forces Snowbirds are in the Comox Valley for their annual spring training. Photo by Erin Haluschak
Suspected bird strike on Snowbirds plane during training in B.C.

Pilot followed protocols and landed the aircraft on the ground without any problems

BCIT. (Wikimedia Commons)
BCIT apologizes after employee’s ‘offensive and hurtful’ email leaked to Métis Nation

BCIT says employee’s conduct has been investigated and addressed

An adult male yellow-breasted chat is shown in this undatd photograph on lands protected in collaboration between the En’owkin Centre and Penticton Indian Band with support through ECCC. The rescue from near extinction for a little yellow bird hinges on the wild rose in British Columbia’s Okanagan Valley, a researcher says. THE CANADIAN PRESS/HO, A. Michael Bezener/ En’owkin Centre 2020 *MANDATORY CREDIT*
Rare yellow birds need wild roses to survive in British Columbia: researcher

The importance of local wild roses emerged over a nearly 20-year experiment

Join Black Press Media and Do Some Good
Join Black Press Media and Do Some Good

Pay it Forward program supports local businesses in their community giving

Cannabis bought in British Columbia (Ashley Wadhwani/Black Press Media)
Is it time to start thinking about greener ways to package cannabis?

Packaging suppliers are still figuring eco-friendly and affordable packaging options that fit the mandates of Cannabis Regulations

RCMP officers search around rows of luggage carts as screens block off an area of the sidewalk after a shooting outside the international departures terminal at Vancouver International Airport, in Richmond, B.C., Sunday, May 9, 2021. THE CANADIAN PRESS/Darryl Dyck
Police say gang conflict in Metro Vancouver may be behind shooting death at airport

Police said this generation of gangsters is taking things to new level and have no regard for community safety

RCMP are looking for information on an alleged shooting attempt near an elementary school in Smithers March 10. (Phil McLachlan/Capital News/Stock)
UPDATE: Man killed in brazen daylight shooting at Vancouver airport

Details about the police incident are still unknown

Most Read