- [Michelle] Hello, and welcome
to the David H. Koch Hall of Fossils "Deep Time"
at the Smithsonian National Museum of Natural History.
My name is Michelle Pinsdorf,
and I'm a fossil preparator here at the museum.
You're probably familiar with paleontology exhibits
of ancient fossils and mounted skeletons,
but how do we really know
these fossil creatures are assembled just right?
And how do these fossils get brought
from the places they were discovered
and into a museum display case?
We can explore these questions
using one innovative section
of our "Deep Time" exhibit
called the Fossil Lab.
On exhibit is this skeleton
of Stegosaurus stenops, USNM V 4934,
a dinosaur from the Jurassic period
that lived about 155 million years ago
and was discovered in 1886 in Colorado.
Unlike most other posed skeletons
you see in "Deep Time,"
this animal's fossil remains
are displayed in situ,
or as they were originally buried.
This excellently preserved animal
was buried whole
with its belly side facing outward.
The head and one forelimb
are to the right and turned downward.
Between the skull and shoulder
are many small round shapes.
These ossicles, or bony studs anchored in the skin,
would have protected the animal's throat in life.
Looking further down the body,
we see the rib cage,
parts of the hind limbs facing downward,
and its most famous feature,
the large armor plates
that extended from the animal's back.
Before this fossil was found,
scientists were not sure
how to interpret these bony plates.
Some thought they laid flat along the body
like roof shingles,
and others thought that the plates
ran down the spine in a single row.
This fossil showed that the Stegosaurus's armor plates
were actually staggered,
lining the spine in two rows of alternating plates.
Skeletons preserved in articulation,
meaning with the bones aligned
in their anatomical positions,
are exceptionally rare.
Most fossils are only found in scattered fragments,
and complete skeletons
require extensive work to reassemble.
This fossil specimen is particularly useful
for understanding posture, joint articulation,
and other aspects of anatomy.
As you can imagine,
getting a fossil this large and this precious
from its discovery location in Colorado to the museum
was no easy task.
Excavators carefully carved out
the rock around the skeleton
to isolate it.
Then, the large block of rock containing the skeleton
was separated into smaller sections.
Each section was removed from the ground,
then wrapped in a protective coating of plaster.
The sections were packed into crates
and transported to Washington, D.C.
Next, the fossil would have been unpacked
and prepared in a laboratory
just like our Fossil Lab.
Here, Smithsonian paleobiology volunteers and staff
work on actual specimens
from our fossil research collection,
the largest in the world.
Fossil preparators undertake
the slow and delicate process
of removing the surrounding matrix,
or host rock,
from fossil specimens.
This is done using a combination of hand tools
and air scribes
which use compressed air
and a pointed stylus
to chip away at rock.
Preparators try to reveal as much of a fossil as possible
without damaging the fragile and heavy specimens.
After preparation, fossils are housed
in foam-lined archival trays,
or in large storage cradles
that are custom-made for each specimen.
Fossils not on exhibit
are organized into drawers
inside of large storage cabinets
in our behind-the-scenes paleobiology department
collection spaces and labs.
Researchers use the vast collections
for scientific study.
These fossils are sometimes loaned
to other museums and research institutions
for study or temporary display.
Scientific illustrators use a microscope
with a special attachment called a camera lucida
to create detailed drawings of fossils
for research publications.
These drawings allow researchers
who may not be able to come see the fossils in person
to know what they look like
and to understand their significance.
This combination of art and science
has been used to convey information
about fossil specimens
since the start of paleontology as a science.
The Fossil Lab is inactive during this tour,
but at the museum,
this space is busy with fossil preparation activity.
Visitors can watch our preparators
working on the fossils
and see science happening in real time.
The preparation work happening in this lab
is exactly the same as what occurs
in the museum's other fossil preparation spaces
and helps us show everyone the intricate work involved
with putting these amazing fossils on display.
All of these tasks are part of the work we do
to care for the Smithsonian paleobiology collections
and to better our understanding of life in the past.
To learn more about our fossil collections,
explore our website,
or check out our other narrated virtual tours
to see more of the "Deep Time" exhibit.