To return to the site click on the logo or use your browser's back button when you are finished. Digging a Dinosaur Click here for printable activity Click here for the answer key Background Information Dinosaur bones are extremely fragile when first discovered in the field. The jacket looks like the white plaster casts doctors make for broken human bones. The plaster comes as a powder and is mixed with water.
Plaster is much stronger if burlap is dipped in it and then wrapped around the bone.
The plaster and burlap, however, cannot be placed directly on the bone because it would be very difficult to remove the jacket later. A separator, like paper, is used to cover the bone before the plaster-dipped burlap is applied. Once the plaster dries, the jacket can be labeled with a permanent marker. It is very important to label the jacket and record its contents in a field book, because the bone can no longer be seen. If the bones were completely exposed in the field, lying on the surface, it would be easy to make a complete jacket all at once, but most bones are buried, and so the jacket must be made in two stages.