When paleontologists dig for fossils, it is often a very long, slow process. They usually work in teams. The entire area that is ready for a dig is roped off and divided into pieces of a large grid. Then, each square is dug out one at a time. Once paleontologists have found a fossil, it has to be removed very carefully from the ground so that it doesn’t crack. Fossils have been in stone for millions of years without being touched by light or air. Even though they are stone, they are very, very fragile and can be broken easily. The first thing a paleontologist will do once she has found a dinosaur bone is photograph it and label it while it’s still in the ground. It’s very important to remember exactly what the fossil looked like when it was found. Are there other dinosaur bones nearby? Are there eggs? Are there footprints? This is how we learn about the way these dinosaurs lived while they were alive.
Most of the top layers of rock are taken away using large tools like picks and shovels. This heavy, top layer of rock is called the overburden. Once that is removed, the 2-3 inches of rock closest to the fossil are removed with smaller hand tools like trowels, hammers, whisks, and even dentists’ tools! Once the fossil is completely visible, it is photographed and labeled again. The way a fossil is dug up from the ground is called excavation.
No matter how large a fossil is, it has to be treated very gently. Fossils can be broken easily. They can crumble into dust before they are even excavated. Many times paleontologists will brush a layer of quick-drying glue onto the bones to make them harder and stronger. Once they are glued, fossils can be removed from the rock more easily. Then the bones are carefully packed into bags or boxes. The packs are labeled so they don’t get mixed up with the bones of other dinosaurs. Large bones are often wrapped in burlap and then smeared with plaster to make sure they don’t break on the way to the lab. This is just what a doctor would do to fix a broken arm! The bones are then taken to the lab. Often the lab is many miles away, in another country. Before a fossil reaches the lab, it might have to travel by plane or boat, truck or train!