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Here's
Part II of our latest dinosaur mission. In the Prep Lab, a Phaeton team
tackles the work of cleaning a treasure trove of dinosaur fossils sealed
in plaster field jackets. For the fieldwork story, check out Part I--Dinosaur
Hunting.
Part I--Dinosaur Hunting |
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Cleaning
a fossil is known as "preparation," or "prep work" in paleontology. So the
laboratory where this takes place is called the Prep Lab. Our team begins
the work by cutting open one side of the field jacket that contains the
dinosaur bone and its surrounding rock. The shell comes off easily because
of the barrier layer of wet paper towels we laid over the fossil when we
were jacketing it. Here Phaeton's Chief Paleontologist Michael Ryan (at
left) and Director of Field Operations Matt Bliss (at right) open the first
of our field jackets from this mission, using a prybar. They wear breath
masks and safety goggles for protection from the plaster dust created by
sawing open the shell.
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it is advantageous to work from the back of the fossil rather than from
the face--if the face is particularly fragile, for instance. In such a case, a field jacket arrives on your workbench "upside down," and so all you see is rock. Where's the fossil? Somewhere inside. Your job is to remove 100% of the rock--and 0% of the fossil.
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Paleo
prep technicians may use a variety of small power hand tools, including
an airscribe (a kind of mini-jackhammer) and an air abrader (a mini-sandblaster). Phaeton's Ancient Historian Greg Aldrete (left) here uses
a dental pick to flake small fragments of rock away from the dinosaur rib
pieces he is working on. We occasionally use dental picks in the field,
but more often you stop with small picks and chisels in the field and save
this kind of fine cleaning for the laboratory, where ideal conditions allow
you to do a better job. |
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consistency of the rock around your fossil will vary. In some places it
may be tough as concrete, in other places it may crumble like dry-packed
sand. To learn prep work you begin very cautiously, picking away at the
rock until you expose the fossil. Just as in the field you pointed your
chisel away from the bone to spare it from damage, here in the prep lab
you are very careful to never scrape the bone surface with your tools. It
is too fragile for that. Instead you use a combination of pressure and abrasion
to flake away the rock around the fossil. If you're lucky--or skilled--this
technique will leave the bone surprisingly clean and with a nice undamaged
surface. As you work at this rock with your fine tools, you begin to realize
how much volume of rock there is in every one of these field jackets, and
you reflect that it is no wonder that the lab work takes much longer than
field work. |
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Paleo
prep work can be daunting at first, since each technician is entrusted with
a fossil that can never be replaced. If you damage yours, that information
is lost forever. And no one knows what may lie under the rock of your specimen.
Skin impressions or other faint fossil evidence could be hidden, and you
don't want to find that out by breaking half of it into powder. A prep tech
learns to get a feel for the rock and to always be on the lookout for what
it may reveal. Though prep work is slow, many people end up enjoying it
very much. Each sample is your own unique puzzle to solve, and if you do
your job right you produce a beautiful specimen of value to science. So
much work is put into the cleaning of every bone that prep workers end up
taking great personal pride in the results of their effort. None of our
team except Phaeton's captain and Michael Ryan had ever done paleo prep
work before, but all enjoyed the experience of learning the craft, and all
brought a professional approach to the important work. Alicia Aldrete, our
field artist, found that her hand-eye skills from using pencil and paintbrush
served her particularly well in the prep lab. So Michael Ryan gave her a
very fragmentary rib to work on, which required extremely delicate work
with tweezers as she gradually removed rock particles from the crumbling
fossil. |
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bones we worked on were very fragile. As we removed rock from around them,
to keep them from crumbling further we used a liquid preservative called
Vinac to give the fossils more strength. The preservative is a polyvinylalcohol
(PVA) in an acetone solution, and when thinned down it will soak into the
pores of a bone fossil like water into a sponge. Matt Bliss applies Vinac
to a dinosaur bone with an eyedropper here (right). When the preservative
dries and hardens it gives the fossil much greater strength. We use thicker
solutions of Vinac like glue to attach broken pieces of bone back together.
These preservatives can be easily dissolved out of the fossil with straight
acetone, so they have no permanent effect on the specimen. |
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centerpiece find was the new dinosaur's skull. The horn fragment that launched
our expedition was the tip of the iceberg, and underground the key piece
of the dinosaur lay waiting. The skull is by far the most important part
of a certaopsian dinosaur because ceratopsian species are very similar in
body shape and different species may sometimes be distinguished by their
skulls alone. In this way they are similar to antelope species in Africa,
which often have very similar "generic" bodies but distinctive antlers.
For Phaeton's Chief Paleontologist Michael Ryan, the skull was crucial because
it was here that he would have the evidence to name a new species and, more
importantly, clarify evolutionary relationships among the ceratopsian dinosaurs
he studies. Fortunately the skull was there at the dig site, but unfortunately
it was crushed, fragmented, and in only fair condition. To clean and prepare
this prize specimen Michael called in one of the most talented paleo prep
techs in the business, our friend and colleague Wendy Sloboda. Wendy would
have to spend months on this giant skull, work that is still in progress.
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The
result of your work as a preparator is a fossil that looks like it never
had any rock encasing it at all. The Vinac you have applied sparingly is
invisible now, and it looks like the broken pieces of the bone hold together
by magic. Brushes and compressed air have driven away the dust as you work,
leaving a clean fossil. And you have successfully avoided ever scraping
the bone surface, so you've produced a beautiful laboratory specimen. The
best paleo prep techs, like Wendy Sloboda, are master artists at this work
and can convert smashed rubble into marvelously complete clues to prehistoric
life. |
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new dinosaur Michael has discovered is related to the Chasmosaurus, seen
here on display at the Field Station in Dinosaur Provincial Park where we
were working. Scientific study of the bones is generally easier before the
bones are mounted. With each fossil lying on a lab workbench you can examine
the bones closely for telltale clues to the living animal's flesh, such
as tendons, and muscle attachment scars which can suggest where and how
large certain muscles were. However, the work of mounting a skeleton for
display has scientific value as well, because this process helps you test
your theories about how the parts of the dinosaur fit together, its probable
life posture, and the ways it was able to move. Good dinosaur mounting technicians
are thus another kind of important scientific artist. Phaeton's David West
Reynolds, Michael Ryan, and Dan Erickson have all done work of this type.
We will explore these stories here on PhaetonGroup.com in the future. For
the time being, our finds from the 2002 field season will remain in the
lab under study. |
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Presently,
Michael Ryan is hard at work writing up the scientific publication of his
new species of dinosaur. We can't reveal the name he has chosen until it
hits print in an academic journal. But we can report that between archaeologist
David West Reynolds and ancient historian Greg Aldrete, Michael was surrounded
by Phaeton teammates who know Greek and Latin, so he was easily able to
devise an expressive and appropriate scientific name. Phaetonosaurus was
suggested but Michael decided against it.
We offer lectures on this subject, for groups or classrooms, so if you'd like to hear more about Phaeton dinosaur hunting directly from one of our team members, please contact us by e-mail (see "Contact Us" in the navigation bar at left).
| There
are many opportunities for an interested volunteer to join paleontological
expeditions in North America. One of the best programs is the "day dig"
program that Michael Ryan ran at the Royal Tyrrell Musem of Paleontology
in Alberta for many years. You can try anything from an afternoon to a weeklong
experience in the field, learn the techniques described on this site, and
contribute to ongoing scientific research. There are programs for children
and adults alike. If you'd like to experience such an adventure for yourself, we encourage you to check out the possibilities. Call the Tyrrell at (403) 832-7707, or e-mail them at info@tyrrellmuseum.com> | | |
