"Thomas" Info

Fieldwork

Most fieldwork takes months of preparation. Besides applying for necessary permits there are many considerations such as travel, supplies, equipment and crewmembers that need to be organized.

Our quest for "Thomas" began back in the summer of 2003. Before going out to the field we had to apply for a collection permit from the Bureau of Land Management. Once approved, we were ready to begin fieldwork preparation. We compiled a long list of supplies and built a team of people that would work together smoothly. Crews of 15-20 people need an amazing amount of supplies to survive out in the field for a month. Camp life can be fun but also grueling. There is no running water for toilets or showers in the badlands and tasks, which normally are simple, such as brushing your teeth, become much more difficult when every drop of water has to be hand carried.

It took 3 days to drive 2 truckloads of equipment, supplies and some of the crew from Los Angeles to Eastern Montana. Once we arrived, we met with the local staff of the Carter County Museum and the farmer on whose lands we would be camping. Navigating the badlands was an adventure and on several occasions, we had to repair parts of the dirt road that washed out in the previous rainy season! Finally, we settled on a spot that we would call home for the next 4 weeks.

Looking for fossils usually involves a lot more walking than digging. Since we already had the coordinates of the butte that contained "Thomas" , we were able to begin our excavation. We had no idea that this Tyrannosaurus rex would be so complete that that it would take another 3 years before we had fully excavated the site! The first task was to make a grid and draw a map of the site. On this, we mapped each of the fossils that we found.

Fossils are as hard as rock, but can often crumble or shatter. To protect them on their way back to the museum, we use toilet paper, plaster and burlap to create a "jacket." Like a cast on a broken bone, the jacket keeps the fossil stable and rigid. In order to jacket a fossil, we dig a trench around the rock containing the fossil and apply wet toilet paper. This prevents the next layer of plaster from sticking to the fossil. Then we wrap the fossil on all sides with plaster covered burlap strips. Once dry, we gently flip the block and cover the other side with plaster. We write a field number on each protected specimen that correlates to our field notes. When the jacket arrives in the lab, we carefully open it to reveal the fossils.

Laboratory Preparation

Time to prepare a specimen varies enormously and can take a few days to years depending on the size and quality of preservation. First, we remove the top half of the plaster jacket with a saw. Then the toilet paper is peeled back to reveal part of the fossil. The preparator uses clues like color and texture to help identify fossil from rock. The rock surrounding the fossil is called "matrix". We have been able to remove some of the matrix surrounding "Thomas" with water, toothbrushes and dental picks. However, much of it is rock and requires power tools such as air scribes (miniature jackhammers) and air abraders (miniature sand blasters) as well as patience to expose the fossil. Once the fossil is removed from the matrix, it is repaired with glue where needed and in some cases the cracks are filled with putty. Finally, we apply a hardener to help stabilize the specimen. By the end of 2006, we had prepared roughly 30% of "Thomas" .

Collections Storage

In some cases, we make fiberglass holders for the larger and more delicate elements such as "Thomas" ’ braincase shown in the photo. This helps to protect and stabilize them while they are in storage in the collection.

All of our specimens, including "Thomas" , are stored in metal cabinets (as shown in the photo) in our collections. Information about each of our specimens such as the name, where and when it was discovered, who discovered it, where it is currently located, etc, is stored on a computer database. We give each specimen a label with a unique catalogue number, which allows it to be easily retrieved from the large collection for research or exhibit.