August 31 , 2016

by Burke Museum

he public can see the T. rex skull in its plaster field jacket, along with other T. rex fossils and paleontology field tools, in a lobby display at the Burke Museum—the Washington State Museum of Natural History and Culture—beginning Saturday, August 20, through Sunday, October 2, 2016. Plan your visit today!

A team of Burke Museum paleontologists discovered a Tyrannosaurus rex! So far about 20% of a full skeleton has been excavated, including a very complete skull plus teeth, ribs, vertebrae, hips, and lower jaw bones. There’s likely more to discover!

The 66.3-million-year-old T. rex was discovered in the Hell Creek Formation in northern Montana—an area that is world-famous for its fossil dinosaur sites. With permits to research and collect on federal land, the team of more than 45 people, led by Burke Museum Adjunct Curator of Vertebrate Paleontology and University of Washington associate biology professor Dr. Greg Wilson, helped excavate the T. rex over the course of a month this summer.

“When we started to see those teeth with the skull, we knew we had a fantastic specimen,” said Wilson. Not only is it a fantastic specimen, it is incredibly rare. Although arguably the most iconic and well-known species of dinosaur, the T. rex skull is one of only about 15 reasonably complete ones known to exist in the world.

Here’s how the discovery unfolded…

A clue on the surface

Two Burke Museum paleontology volunteers, Jason Love and Luke Tufts, were looking for signs of fossils on federal land managed by the Bureau of Land Management (BLM) in the Hell Creek Formation when they stumbled upon a large scattering of bone fragments on the surface of the sandstone.

Upon further inspection, they noticed large fossilized vertebrae sticking out of the rock. The large size of the bones along with their honeycomb-like internal appearance indicated that they belonged to a carnivorous dinosaur.

“At this point, we knew it was a dinosaur because of the size—there were no other vertebrates on the land that were this size,” said Wilson. They suspected it might be a T. rex but couldn’t yet be sure…

The team of Burke paleontologists and volunteers got to work preparing to excavate the fossils after aquiring permits from the BLM. They were in the area collecting fossils as part of the Hell Creek Project, a multi-disciplinary project examining vertebrates, invertebrates, plants and the geology of the area to learn more about the period of time immediately before and after the mass-extinction event that killed off the dinosaurs and gave rise to the age of mammals.

First the team, led by field crew chief and postdoctoral researcher Dave DeMar, needed to remove about 20 tons of rock from the hillside—a section nearly 16 feet in width—so they could create a ledge at the level of the fossils. This grueling task took a team of eight to ten people nearly two weeks of continuous digging with jackhammers, axes and shovels.

Several feet away from the ribs, the team came across an incredible find—a skull! As they chipped away the surrounding sandstone, they could see fossilized bone emerging with a keyhole-shaped opening, that was unmistakably the back (squamosal bone) of a T. rex skull.

That’s when all of the pieces fell into place (so to speak). The team had indeed discovered a T. rex!

“The combination of the skull features, the size of the bones, and the honeycomb-like appearance of the bones tell us this is a T. rex,” said Wilson. “This was a very exciting moment for us.”

Several members of the team visited the nearby Fort Peck Interpretive Center to compare the skull they had found to existing T. rex museum specimens. Sure enough, the keyhole-shaped opening peeking through the rock was an anatomical match to other T. rex fossils on display at the Center.

http://www.burkemuseum.org/blog/burke-museum-team-discovers-t-rex