Multi-tasking in the UCMP Prep Lab

by Jane Mason, Senior Preparator — (page 1 of 3)

“Screech . . . screech”—the sandpaper grates across the plaster, making my ears wince and sending up little clouds of dust and embedded fiberglass. “Mike, you should be wearing a mask when you’re doing that!” I called to the student working in the lab.

Mike is sanding the edges of a storage jacket for a Triceratops tail that was found in Montana a few summers ago. To create the jacket, we partially buried the tail vertebrae in our sandbox to hold them in their natural position. Then we covered them loosely with a sheet of plastic wrap as protection from the oncoming plaster. We dipped small squares of thin fiberglass sheet into the plaster, one by one, and laid them gently over the vertebrae. We smoothed the fiberglass /plaster with a brush or a gloved hand, so that the plaster conformed to the shape of the bones. Making jackets like these is an important way to preserve our collections from the occasional jostling that occurs in the course of being studied. The jacket also provides increased stability when the specimen is moved, and it offers a protective margin of material to ward off any bumps or collisions with other fossils in case of an earthquake.

But storage jackets are usually the last thing the Prep Lab does for a fossil. After working in the lab for nearly two years, Mike knows the process well. He first came to the Lab as a freshman volunteer and did “hard time” removing grains of sand. This tail was one of his first projects and required removing the surrounding matrix grain by grain, and gluing each little fragment that crumbled off back into its proper place. Then he

Student volunteer Mike deSosa likes to free the bones from their surrounding rock, a slow job requiring a lot of patience. (photo by Jane Mason)

had to scrape the hardened glue from his fingers, so that he could feel the next pieces to pick up! Cleaning the 12 caudal vertebrae and assorted chevrons took Mike four months. Patience is an important requirement in preparation. Though patience is mandatory, the techniques of fossil preparation require a wide range of strategies and protective measures and a variety of tools and equipment: fume hoods, goggles, lots of gloves and masks, and the occasional Band-Aid. After a summer of fieldwork, the fossils arrive in the Prep Lab wrapped in plaster bandages (jackets).