Tyrannosaurus dinosaurs may not have been solitary predators for so long, but they look more like social carnivores, such as wolves, new research announced Monday revealed.
Paleontologists developed the theory as they studied a mass tyrannosaurus death site found seven years ago at the Grand Staircase-Escalante National Monument in southern Utah, one of two monuments the Biden administration plans to restore to full size after what former President Donald Trump has downplayed.
Using geochemical analysis of the bones and rock, a team of researchers at the University of Arkansas determined that the dinosaurs died and were buried in the same place and were not the result of washing fossils in several areas.
Kristi Curry Rogers, a professor of biology at Macalester College, said the research was a “good start”, but more evidence would be needed to establish that tyrannosaurs lived in a social group.
“It’s a little harder to be so sure that this data means that these tyrannosaurs lived together in the good old days,” Rogers said. “It is possible that these animals lived in the same neighborhood with each other without traveling together in a social group and gathered around dwindling resources as times became more difficult.”
In 2014, paleontologist Bureau of Land Management Alan Titus discovered the site, which was later named the Rainbows and Unicorns quarry because of the wide range of fossils contained inside. Excavation has been underway since the site was discovered due to the size of the area and the volume of the bones.
“I consider this a lifelong discovery for me,” Titus told reporters during a virtual press conference. “I probably won’t find another site as interesting and scientifically significant during my career.”
The new site in Utah is the third mass tyrannosaurus site to be discovered in North America and provides even more evidence that tyrannosaurs may have lived in groups, Titus said.
The theory of social tyrannosaurs began more than 20 years ago, when more than a dozen tyrannosaurs were found at a site in Alberta, Canada. Another mass death site in Montana has once again raised the possibility of social tyrannosaurs. Many scientists have questioned the theory, arguing that dinosaurs did not have the power of the brain to engage in sophisticated social interaction, Titus said.
“Taking the next step in understanding the behavior and behavior of animals requires truly amazing evidence,” Joseph Sertich, curator of dinosaurs at the Denver Museum of Nature & Science, told the news conference. “I think this site, the spectacular collection of tyrannosaurs, but also the other assembled evidence … pushes us to the point where we can show some evidence of behavior.”
In addition to tyrannosaurs, the researchers also found seven species of turtles, several species of fish and rays, two other types of dinosaurs and an almost complete skeleton of a juvenile alligator Deinosuchus. These other animals do not appear to have died all together.
Paleontology groups have been among those pushing the federal government to restore the Bears Ears and Grand Staircase-Escalante National Monuments to their original size to protect the region’s rich paleontological and archaeological records.
Interior Secretary Deb Haaland visited southern Utah earlier this month, preparing to make recommendations on reversing Trump’s decision to cut monuments. Titus said he showed Haaland a few fossils at his lab during her visit and said he “appreciates seeing the material.”
“(The Land Management Office) protects these fossils as national treasures,” Titus said. “They are part of the story of how North America came to be and how final we came to be.”