In early September, dinosaur diggers arriving at the Nail Quarry saw nothing but enormous white blobs sticking out of the gray mudstone halfway up a ridge in the middle of nowhere.

The characteristic jet-black color of Late Jurassic dinosaur bones wasn’t visible anywhere because the fossils that had already been discovered were smothered by several layers of tin foil, burlap and plaster, only to be uncovered again in the safety of a museum laboratory.

The white blobs are what paleontologists call jackets. They’re large, awkwardly shaped, covered with sharp edges and extremely heavy, but it’s the best way anyone’s discovered to recover the fragile fossils they discovered.

“Plaster jacketing was invented somewhere in this area,” J.P. Cavigelli, the collections specialist at the Tate Geological Museum at Casper College, told Cowboy State Daily. “I think they used rice flour and muslin back then, but the technique was first used for the fossils found on Como Bluff.”

Plaster jacketing is a vital process at the end of any season of dinosaur discovery. It’s incredibly messy, but everything’s messy in paleontology.