How are dinosaur fossils prepared in the laboratory?

Fossil preparators are highly skilled technicians who restore the naturally fractured bones and teeth of fossil to the original state, just as art conservators restore damaged paintings and sculptures. When fossils arrive from the field, they are encased in plaster jackets and the rock—or matrix—which was deposited around the fossils. Fossil preparation involves cutting open the plaster jacket and removing this matrix surrounding the fossil. The matrix may be soft and crumbly, when the sand or mud is poorly cemented together, or it can be extremely hard, when the sediments are well cemented.