July 22 , 2016

by Sarah Blakely

Pete Larson, the president of the Black Hills Geological Institute in Hill City is not just living his own dreams, but those of every little kid everywhere, getting dirty, exploring the Badlands, and digging up dinosaurs.

He’s one of the most prominent paleontologists in the world, digging up hundreds of fossils from dozens different species over the past 60 years. In fact, he discovered his first fossil at the age of four.

Now, another monster has been unearthed.

“We had a museum that had called and asked to get a t-rex for the museum, and not only just to get the t-rex, but also to help collect the t-rex,” explained Larson. “It was a very special request, so we kept our ears to the ground and found out about this dinosaur being discovered.”

The newest 41-foot-long tyrannosaurus rex is named Trix, after the Netherlands’ Queen Beatrix, which is where she’ll be going after she’s pieced together.

Trix was discovered on a ranch in Montana back in 2013, just one year after the museum’s request. Although only a little more than half of her bones were traced—approximately 54 percent—she’s the third most complete t-rex ever found following behind South Dakota’s most famed t-rexes, Stan and Sue.

“She’s just a little bit shorter at the hips, but she weighed approximately one-and-a-half times what Stan weighed, so she was a big girl,” said Larson.

To up the scare factor, Larson and the museum have a few tricks of their own for the tyrant queen.

“Working with the museum, together we came up with this plan of having this t-rex kind of sneaking around a corner, running around a corner with the head low, perhaps to grab something like a small child running in front of it.”

Normally when you see a t-rex in a museum, it’s standing upright, but what you might not know is that the skull you see on the skeleton is not the real skull. The real skull can weigh about 400 pounds, and it’s too heavy to be lifted up that high and is so valuable to scientists, so they use a cast on the skeleton.

But Trix is a little bit special.

“This will be the first t-rex with an original skull mounted on its original skeleton,” Larson bragged. “It’s one of those milestones that’s kind of fun to be able to do.”

But the evolution from fossil to fearsome is a monster of a project.

“We map the bones as they’re coming out, and sometimes you have to follow this trail of bones for a long ways. But you can’t just excavate one of these bones and pick it up because it will fall into thousands and thousands of pieces,” he said. “So we have to cover the bones with a plaster jacket, which helps preserve their integrity, and we transport them back to the Institute.”

That part of the process can take anywhere from a few weeks to a few years. For Trix, it was just three weeks from land to lab.

“Once they’re back in the lab, we basically do more of the fine work. We keep uncovering the downside of the bone first, and gluing it and gluing it, maybe cleaning it with our air-abrasive machine, which uses sodium bicarbonate 50 micron-sized particles of dust that blast away the rock, but leave the bone. That process takes a long time. We collected Trix in 2013, and we’re just now finishing up the last bones,” Larson explained.

And finally, assembling the prehistoric puzzle.

“We have to have steel supports because even though we’ve put literally gallons of super glue into this dinosaur, we still need to support those bones because they don’t have the same integrity they did when they were living animals, so we build a steel frame,” he said. “We also don’t want to drill the bones and put the steel inside the bones because it makes them much more difficult to study. Plus it actually destroys some of the potential information. So we have to make these special little saddles to hold the bones.”

After it’s all put together, they take it back apart, package it, and ship it to the museum with an instructional video tutorial. Larson says the time it took to prepare Trix for her new home is typical of most dinosaurs they find, but because they had a deadline to work with, Trix became a top priority.

Then it’s back to square one, digging up the next big thing.

“There’s still tons of things that I want to do, and still lots of projects that we’re right in the middle of,” Larson said. “I cannot imagine retiring because I’ve been retired for basically my working life.”

Trix will be shipped to the Naturalis Biodiversity Center in Leiden, Holland this August. She will be put on display in the museum in early September.