October 31, 2016:

by CHRIS ROGERS

Winona State University (WSU) professor Lee Beatty and his students were about to leave when they found it. Beatty and his pupils have spent the last three summers digging up dinosaur bones in the badlands of North Dakota — mostly fragments from the shield-like frills of Triceratops and other bits of the ancient plant-eaters’ bodies. They were working to button up the dig site for winter when they spotted something small and pointy among the dust-colored rock. It was not a Triceratops horn.

Beatty, WSU students, and other members of the dig organized by WSU alumni discovered the tooth of a juvenile Tyrannosaurus Rex.

“We found this Tyrannosaurus Rex tooth just sitting among the bones,” Beatty said, still sounding a little incredulous. “That was pretty cool.”

Beatty and the students also unearthed the tooth of a Dakotaraptor, a recently discovered cousin of the velociraptors made famous in the Jurassic Park films. The two finds are exceedingly rare, something paleontologists could spend years looking for.

“We don’t come across these larger predators very often,” Beatty said. “When you get a payoff like this, it’s always really exciting,” he added.

The first Dakotaraptor remains were not found until 2005, and papers describing the new species of raptor were only published last year. Normal velociraptors — the kind that scientists have been digging up in Asia for decades — are actually quite small, around the size of a dog, but in Jurassic Park, filmmakers depicted much a larger, meaner creature, similar to the horse-sized Dakotaraptor.

People can tell a lot about a dinosaur — or extinct mammal — from its teeth. Last week, WSU geology students held up the railroad spike-like tooth of an adult Tyrannosaurus Rex and the flat molars of a wooly mammoth. One is meant for crushing bone and the other is for calmly chewing up plants. The students completed an assignment, deducing dinosaurs’ eating habits based on their teeth, and Beatty showed student Katie Kraus the differences between the massive teeth of an adult Tyrannosaurus Rex teeth and the slender, juvenile Tyrannosaurus Rex tooth his summertime students discovered.

“We think this tooth is really meant for just indiscriminate punching through bone and crushing stuff,” Beatty said, holding up the adult tooth. “Juveniles didn’t go in for this big, bone-crushing kind of eating. They did more of this selective slicing,” he added, showing off the juvenile’s more slender tooth.

As tyrannosaurs matured, their eating habits changed, Beatty explained. The juvenile T-Rex tooth looks a lot like a slightly larger version of the Dakotaraptor tooth, and Beatty said that while full-sized tyrannosaurs were in a class of their own, juveniles may have competed with Dakotaraptors for prey.

The T-Rex and Dakotaraptor teeth were found at a dig site full of Triceratops' remains. Were the T-Rex and Dakotaraptor feeding on those Triceratops? It is hard to say, Beatty responded. The fossils were found in what is called a “microsite,” a place where lots of fossils from different animals wash up, such as a bend in a river. Microsites give a great snapshot of the kind of biodiversity that existed 66 million years ago, but it is hard to tell whether the different animals found there died at the same time or in the same place.

Freshman Samuel Ehlinger identified as a “hardcore” dinosaur nerd when he was a young boy. “Seeing this stuff is really awesome,” he said. Sophomore Steven Granquist added, “It’s pretty crazy seeing teeth this big and thinking how big the animal it came from must have been. Holding teeth the size of my head is pretty crazy.”

WSU does not offer paleontology courses, per se, but the study of ancient life is a big part of several introductory and advanced level geology classes, Beatty explained. He hopes to spread the word to students about the opportunity for students to go to the Dakotas for class credit or research projects in the summer. Hell Creek Fossils, the company Beatty partners with for the digs, is run by WSU alumni who offer a sort of all-inclusive dinosaur digging vacation package for dinosaur lovers.

It is a pretty special experience, Beatty said. He explained, “When you excavate this material, it’s been buried in the ground for 66 million years and you’re the first person whose seen it ever.”