May 22, 2012

Unearthing a Fossil: Giant Turtle Edition

We're often asked what it takes to get a fossil out of the ground and ready for research and museum display. The answer: it can take weeks, months or even years worth of work.

In this short time-lapse video, Burke Museum fossil preparator Bruce Crowley walks us through the process with our giant turtle fossil—from digging it out of the ground and wrapping it in a jacket, to chipping away tiny bits of rock with a series of miniature jack hammers.

When we first introduced you to our giant turtle a few months ago, Bruce and a team of volunteers were just starting to carefully chip away at the rock here in our lab. Now, after a lot of work, nearly half of the fossil is exposed...including a complete skull!
The only known complete skull for this species.
Our "giant turtle" is now known to be a softshell turtle of the genus Axestemys belonging to the family Trionychidae, and is estimated to be about 49 million years old.

This fossil is unique because it contains the only known complete skull for this species, along with several complete limbs. Plus, it's giant! Based on what we can tell about its size at this point, it may be the largest fossil turtle in our collection.

So what's next for the turtle? Bruce's team will start chipping away rock from the other side of the fossil. To do this, they'll apply another side of the jacket (aluminum foil and toilet paper covered in a layer of plaster) to protect the exposed fossil and gently flip the turtle over.

Eventually, the fossil will be available for turtle paleontologists and other researchers to study, and could even be on display here at the Burke Museum.

By Cathy Britt, Digital Communications