Reconstructing the past
Paleontologists find fossils in sedimentary rocks, but they don't just dig a hole hoping for the best. They spend a lot of time with their eyes to the ground, looking for bones eroding from the sediments, then work slowly and carefully to uncover them.
Even though fossils are made from minerals, they are very delicate. Special chemical preservatives, often plastics dissolved in acetone, are used to harden the bones as they are uncovered, because they can disintegrate after exposure to the open air. As the acetone evaporates, the plastic hardens and holds the fossils in place.
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Discovery of the fossils
Paleontologists uncover fossils in the field and bring them back to the lab, where technicians use special tools to carefully remove sediment and may harden the bones with chemicals. This fossil shows a Scaphognathus studied by August Goldfuss in 1831.
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Reconstructing the fossils
Most fossil skeletons are incompletely preserved, but paleontologists use two ways to fill in the gaps. The easiest method is mirroring known bones from the left or right side. When that is not possible, they rely on related animals as a guide.
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Reconstructing the living organism
After the skeleton is reconstructed, paleontologists use comparative anatomy to identify the locations of muscles, and exceptional fossils to reconstruct the skin. With this method, they predict how Scaphognathus would have looked in life 150 million years ago.
Skeleton and life reconstruction art by Julio Lacerda.
