We answer a lot of questions at FossiLab. Here are some of the most common ones:
|Are the fossils real?|
All of the fossils that we work on in FossiLab are real. The Last American Dinosaurs exhibit that surrounds the lab includes both real fossils and precise replicas of fossils. You can tell the replicas because they are labeled as "casts."
Why do we exhibit casts? Some fossils are extremely fragile and all are subject to damage by vibration and changes in temperature and humidity. Because the rarest and most historically important of our fossils are irreplaceable, we exhibit casts of these, storing the real fossils under more controlled conditions that preserve them for future research. We also exhibit casts of important specimens that are owned by other museums. Few skeletons are found 100% complete, and many ancient animals are known only from incomplete skeletons, so it is not uncommon for a museums to share replicas of particularly good specimens.
In the past, visitors to the National Fossil Halls, which are undergoing renovation, sometimes noticed cast bones or sculpted models of bones that had been incorporated into real fossil mounts. By including replicas of missing bones, we were able to exhibit more "complete" skeletons, giving visitors a better sense of what the ancient animals looked like. A good example is the Teleoceras, an extinct North American rhinoceros (shown right, above), that was exhibited near the FossiLab door in the 'Mammals in the Limelight' hall. This skeleton was composed of both fossil and sculpted material. Note that most of the ribs are fragmentary, with plaster filling in for missing bone. The Giant Ground Sloth, (shown right, below) in the 'Ice Age' exhibit is another example. You can see that missing portions of the lower jaw and cheek bones were sculpted in plaster when this fossil was mounted for exhibit.
Historically, it was common for museums to mix and match bones from different individuals in order to create complete mounted skeletons. Unfortunately, the bones weren't always well matched in size, and this could introduce inaccuracies into the way the mounts were positioned. Today, paleontologists agree that proportionally accurate casts of skeletons give a better impression of reality than chimeras pieced together from actual fossils. This linked webpage shows how our mounted Triceratops skeleton was updated with casts to meet this new standard.
|How do you know how old the fossils are?|
Scientists can learn the age of rocks using an accurate and reliable method called radiometric dating, which compares the observed abundance of naturally-occurring isotopes and their decay products. Used in tandem with traditional geologic principles, such as the principle of superposition, the numerical age of virtually any rock formation, and by extension, any included fossils, can be determined. Visitors to FossiLab will find more information about dating methods at the base of the Tower of Time near the entrance to the Dinosaur Hall. Online resources are available on the Department of Paleobiology website. Follow this link and click the yellow "Dating Methods" tab at the bottom of the web page.
|How long does it take to remove the rock covering the fossils?|
The amount of time it takes to prepare a fossil varies depending on the size and complexity of the specimen as well as the nature of the rock matrix that encases it. A small specimen such as a leaf might be uncovered in only an hour or two, but a large, complicated skeleton encased in very hard stone might require a few years of painstaking work. All of the work in FossiLab is done by volunteers who have received special training and work in the lab part time.
|How can I become a paleontologist?|
If you are in high school or younger, take lots of science and math in school and work hard to get good grades. Work on your reading and writing skills so that later on you will be able to communicate your ideas and research discoveries clearly to others. Start to learn about fossils and how to find and identify them by joining a local fossil or geology club and going on collecting trips. Consider becoming a junior member of professional organizations such as the Society for Vertebrate Paleontology. In college, study as much biology and geology as you can. Gain more experience (and perspective on paleontology careers) by volunteering to assist researchers in their labs or in the field. It is likely that you will need to earn a Masters or PhD degree in geology or paleontology if you want to pursue paleontology professionally, but if that is not a possibility you still can contribute to the field. Self-educated amateur paleontologists have made many important discoveries and collaborated with university and museum scientists to write papers and publish in scientific journals.
|What is the dinosaur on the FossiLab logo?|
It is a baby Compsognathus, a small carnivorous theropod that lived during the Late Jurassic.
This fanciful image drawn by paleoartist Mary Parrish shows a preparator using a pin vise and carbide needle to remove rock matrix covering the bones of the animal's right leg and tail. The middle section of the dinosaur is show partially "reconstructed" with a life-like arrangement of muscles covering the bones. At the front end, the reconstruction has been completed by the addition of skin and very fine, hair-like feathers. You can learn more about creating life-like images of dinosaurs by visiting the Reconstructing Extinct Animals page of the Smithsonian's Dinosaurs in Our Backyard website.
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