Teenage Dinosaur Fossil Discovery Reveals What Puberty Was Like for a Tyrannosaur

An artist's impression of what a Teratophoneus dinosaur would have looked like. Nobu Tamura/Wikimedia Commons

You may regret photographs of your awkward teenage years, but at least they won't be fossilized for people to dig up 76 million years from now. Paleontologists are thrilled a dinosaur didn't get quite so lucky, because it means they were able to discover a remarkably well-preserved tyrannosaur skeleton.

Scientists have been digging in Utah's Grand Staircase-Escalante National Monument for two decades now, and they've found other fossils belonging to the species they expect the new discovery to represent. But this one is an adolescent dinosaur and in very good condition, two features that make it extra special.

The team still needs to finish uncovering the bones before they can make real judgments about what the discovery represents. "When you first find these fossils, often they're very sort of unremarkable-looking, because most of the time very little of the fossil is exposed," Randall Irmis, a paleontologist at the Natural History Museum of Utah, told Newsweek. "Once you start uncovering a little bit and you see that hey, a lot of these bones are still connected in life position, you start to get excited."

That's the case with the current example, which Irmis says he expects belongs to a species called Teratophoneus curriei, a relative of the famed Tyrannosaurus rex that followed it about 15 million years later. (Like its more famous follower, T. curriei was a voracious carnivore with stubby, two-fingered arms.) The paleontologists know they're missing the tip of the tail and maybe a couple of toes, but they're confident they have at least three-quarters of the dinosaur's skeleton.

That includes the skull, the bones of which are still connected precisely as they were when the tyrannosaur was alive. "I can already say that based on what we saw in the field, the skull looks absolutely spectacular," Irmis says. That's convenient, since the skull will play a key role in the scientists' final identification of the dinosaur's species.

The dinosaur, which is referred to as a subadult, likely died when it was between 12 and 15 years old. "People often get the most excited about new species being found, but it's actually really critical to have many specimens from different life stages," says Irmis.

Scientists already have a slightly younger and a slightly older T. curriei, but filling in the gap those two specimens left will show Irmis's team how quickly it grew and how its skeleton changed as it did so. The new specimen had grown to almost 20 feet long by the time it died, and was likely buried in a river or floodplain.

That said, the scientists won't be able to absolutely confirm the dinosaur's species until they finish removing the rock around the bones. Excavation in the field focuses on finding just enough of the bones to dig around them; then everything is shipped to the lab still encased in rock, in order to protect the fossils.

A portion of the new fossil discovery. Mark Johnston/NHMU

Irmis and his colleagues now need to carefully remove that rock to view the fossil's details. "Really, we still have the majority of work ahead of us, even though we've already finished the excavation," Irmis says. He estimates it will take as many as 10,000 person-hours of work to prepare the entire fossil.

Once the process is complete, the bones will offer another window onto the region's past. Irmis says that when the tyrannosaur was roaming around Grand Staircase-Escalante, the area would have looked nothing like the high-elevation desert it is today. Instead, the teenage dino would have explored brilliant green swampy forests similar to Louisiana's bayous.

The national monument where the fossil was found has been in the news this year, in President Trump's quest to roll back public lands. President Clinton's decision to create a national monument in 1996 was controversial at the time, and the region's status remains so today, despite its unique geology and paleontology. "These species that we're finding in Grand Staircase-Escalante National Monument, whether they be dinosaurs or crocodiles or turtles or mammals, they're only found in this one place," Irmis says. "They're found nowhere else on Earth."