Book 5, Question 36
Copycat Bones! Why Do Museums Use Casts?
A cast is a copy of a real fossil bone. Real fossils can be heavy, fragile, and hard to replace, so museums often build displays with casts. The real bones stay safe for scientists to study.
More fun facts
- A cast is made from a very exact mold shaped directly from a real fossil.
- Some copies are 3D prints made from CT scans and other kinds of scans.
- If a bone is missing, it is sometimes carved like a sculpture, which is less exact than a cast.
- Real bones as big and heavy as SUE the T. rex's can be hard to handle, so scientists sometimes study a hollow plastic cast instead.
- Mounted casts of SUE have visited museums across the United States and in dozens of other countries.
- At the Field Museum in Chicago, visitors can touch Máximo, a cast of a giant titanosaur made of resin and fiberglass around a metal frame.
- Museums use signs and labels so you can tell which bones are fossils and which are casts.
Sources: fieldmuseum.org
Questions kids ask
Is a museum cast a fake?
No. It is a careful copy made from a mold of the real fossil, and labels tell you which is which.