December 20 , 2016:

by Burke Museum

Just look at those teeth! The Burke paleontology team is preparing a portion of the lower right jaw from the 66.3-million-year-old "Tufts-Love" Tyrannosaurus rex that was discovered this summer and it is an incredible fossil!

Unlike our human jawbone, reptile jaws are made up of several bones. This 3-foot portion of the lower jaw is approximately two-thirds of the animal’s total jaw, which would likely have been four-feet long.

The team hasn’t yet started to prepare the massive 2,500-pound T. rex skull and plaster field jacket that was on display in our lobby earlier this year (more on that in a minute). Instead, they began preparing these smaller fossils first to see the condition of the bone and to get a feel for how easy or difficult it is to remove the sandstone surrounding it.

Reptiles lose and replace teeth constantly throughout their life. When they lose one tooth, another comes in behind it. Notice in the photo above that there are teeth at various heights or stages of replacement.

Overall, the T. rex fossils appear to be incredibly well preserved, much to the delight of our paleontology team. There is one large crack through the lower jaw and a tooth where the roots of modern plants pushed through the fossil causing damage, but otherwise there are only a few minor surface cracks.

Preparation on the jaw is nearly 90% complete at this point, largely thanks to the help of two volunteers—Gary Livingston and Jean Primozich. The team worked on the lower jaw in shifts over the past several weeks, spending more than 100 total hours removing sandstone from the fossil.

It is common to have some minor surface loss when chipping away hard rock from fossilized bones, but that hasn’t been the case with this specimen. “The sand would just pop loose,” Gary said while describing the preparation process.

Next up: More T. rex

Later this week, the team will carefully flip the lower jaw over to finish removing sandstone from the other side. (Hint: You can see the complete lower jaw in person at the Burke’s Dino Weekend, March 11–12, 2017!)

Starting with the lower jaw of the T. rex has given the paleontology team a valuable opportunity to practice on something smaller before turning their attention to several larger specimens, including the T. rex ribs and the massive skull. The relatively easy removal of the sandstone is a welcome sign for what’s to come!

Once the entire skull is prepared, we plan to put it on display in New Burke Museum opening in 2019. “I think we’re all looking forward to seeing this amazing fossil on display in the New Burke Museum,” said Christian Sidor, curator of vertebrate paleontology.

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The Tufts-Love T. rex fossil was collected with permits to research and collect on federal land managed by the Bureau of Land Management (BLM) in the Hell Creek Formation. Read more about the T. rex discovery.

See the T. rex lower jaw in person! Mark your calendars for Dino Weekend, March 11-12, 2017. Event pre-sale timed tickets will be available in early 2017.