Page 89 - DINOSOUR ATLAS

dinosaur facts
Excavation and Display

When a dinosaur fossil is discovered, it is usually a confusing mess of bones
that have been pulled apart by scavengers or swept into a heap by the
elements. Once the bones are exposed, the first job is to record their exact
positions and any details of the site, since this may provide valuable clues
about the animal’s anatomy or life. Only then can excavators carefully remove
the fossils, clean them up in the laboratory, and analyze and preserve them. d exposing the bones
They may then be used to make a replica skeleton for display in a museum. The bones are usually buried beneath layers of rock.
The upper layers may be scraped off by machines,
but the excavators remove the lower layers very
carefully, using fine hand tools. They then place a
wire grid over the exposed bones to divide the site
into smaller areas that can be accurately mapped.
Every bone is numbered and photographed.

d removing the bones
Dinosaur fossils are often fragile, so each one is
painted with resin, wrapped in cloth, and
coated with wet plaster to strengthen it.
When the plaster sets, the excavator can
dig beneath the bone to remove it,
and plaster the other side.

A sAuropod limb bone
is being carefully coated
with plaster

u in the laboratory u fine cleaning
Encased in its plaster field jacket, The fossil is carefully cleaned up
the bone is taken to the laboratory using a variety of tools. This
where the plaster is cut off with a technician is working on
special saw. The technicians then Tyrannosurus teeth with a vibrating
get to work on the fossil, using needle, but other methods include
small pneumatic drills to remove blasting fossils with compressed
surplus rock. air containing soda crystals.
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