BONEDIGGER’S SPECIAL

Joining a dinosaur dig is a child’s dream and also something many adults would jump at if given the opportunity.  What do you need to be good at in order to excel in the pit, uncovering and removing dinosaur bones? Paul and Dave are often asked questions along these lines.

In this section, you will find valuable inside tips from Paul and Dave, paleontologists with a lot of experience in the field, as they take you through the process, step-by-step.

Fabrice gets up-close and personal during excavation
and always keeps a clean workspace.

Excavation often involves discovering fragile dinosaur bones in solid rock.  How can this be done, if you need to dig blindly with an awl or chisel at the start before you have spotted any bone?  The talent to develop here is to be ready to stop what you are doing in a flash.  Often the beginner will hack halfway through a bone before realizing that they have encountered anything but rock.  The result is dozens of fragments of bone  rather than one small chip that can be glued back in place.  Secondly, the beginner will often loose fragments in a large pile of rock debris that should have been cleaned away from the work area.

Tip 1: Be able to stop quickly at the first sight of fossil bone.

Tip 2: Brush loose rock away often to keep your work area clean.

The fossil bones at a site are often in a complex arrangement that becomes apparent only after some cleaning has taken place.  After a site map has been drawn to record the locations of all of the bones, blocks of bone-filled rock called “pedestals” are created by chiseling the surrounding rock away.  The experienced digger finds the right-sized block, protects delicate areas, and does not over-clean the fossils.  Detailed work is better done in the laboratory.  No matter how beautiful or interesting the fossil might be, the risk of damage is substantial.

Tip 3: Avoid detailed cleaning of fossils in the field.

Paul uses foil as a separator to protect the rest of the theropod skeleton before adding layers
of plaster-soaked burlap.

Before applying a plaster and burlap shell, or jacket, a protective layer is needed over the bone so that the plaster will not stick to it.  The experienced digger will make sure that all bone surfaces are covered with foil or paper, and that small packets of fragments are put inside the jacket.  In this way, the plaster will not stick to the bone, and any associated fragments will not become lost in transport. 

Tip 4: Make sure all bone surfaces are covered with paper or foil.

 Tip 5: Include associated fragments in the jacket so they don’t get lost.

Wet burlap absorbs plaster much better and makes a stronger jacket.

Burlap strips combined with plaster make a very hard jacket.  The experienced digger wets the burlap strips before submerging them in plaster, so that the strips absorb the plaster.  Dry strips or strips that are not fully soaked will not unite with the plaster to make a strong jacket.

Tip 6: Soak  the burlap so it better absorbs the plaster.

Mixing the plaster into the water leads to a smoother mix.

Plaster comes as a powder that becomes very hard when mixed with water.  The two must be mixed well; it is a chemical reaction.  The experienced digger sprinkles plaster powder into a bin or bucket of water, so that the plaster is smooth.  Pouring water into plaster powder often creates unmixed lumps that are difficult to disperse and will not become hard.

Tip 7: Mix the plaster into water, not the reverse.

Paul uses his fingers to fit the bandages
snugly over the rock and fossils.

The jacket protects its contents from movement when it is well fitted to the block containing the fossils.  Experienced diggers will use their fingers to fit the bandages to the form of the block.  Spaces inside the jacket are dangerous for the fossils, because they allow movement. 

Tip 8: Make plaster bandages snug.

The large pick makes a trench fast but is safe to use
only after the fossils are covered.Trenching

Making a jacket around and underneath a fossil requires a deeper and wider trench that at first seems necessary.  The experienced digger uses a pick to clear a wide margin around the fossils, once they are protected.

Tip 9: Make the trench deeper and wider than seems necessary.

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