Processing, please wait...
It was processed successfully!
It was processed successfully!
Login Create Free Account
Create Free Account

Cast Fossils Definition

Cast fossils form when minerals or sediments fill molds and harden. For example, a leaf mold fills and hardens, creating a leaf-shaped fossil.

View Lesson on The Fossil Record
Grades 6-8 VideoThe Fossil Record player orange
Preview Only
Oops! It looks like your security settings are blocking this video 🙁

If you are on a school computer or network, ask your tech person to whitelist these URLs:
*.wistia.com, fast.wistia.com, fast.wistia.net, embedwistia-a.akamaihd.net

Sometimes a simple refresh solves this issue. If you need further help, contact us.


The Fossil Record

Fun Facts

  • Cast fossils can get filled in with minerals, forming solid rock.
  • Cast fossils keep the shape of the organism.
  • Weathering or erosion is needed to expose cast fossils to the surface.

Why Do We Need To Know About Cast Fossils

Learning about cast fossils helps us understand Earth’s history and why these fossils are important for science. Cast fossils are made when minerals fill up the space left by decayed organisms, creating a solid copy of the organism. This helps scientists learn about what life was like millions of years ago, including how creatures evolved and how the environment has changed.

This knowledge is useful for people like paleontologists, geologists, museum workers, and teachers. They use cast fossils to do research, teach others, and learn more about our planet’s past. Knowing about cast fossils connects classroom learning with the real world, showing why they’re important for science and education.

Frequently Asked Questions

How are fossils discovered?
Earth processes like erosion and earthquakes can move sediment from one location to another, often uncovering and exposing fossils. Scientists also concentrate their search efforts in areas that are known to have lots of fossils, like Utah.
How do trace fossils provide evidence of past life?
Trace fossils provide information about how an organism lived, including but not limited to how it moved, what it ate, and where it lived.
How do layers of rock provide information in the fossil record?
Over time, sediment forms layers beneath the Earth’s surface. The deeper fossils are found in the Earth’s crust, the older they are. The closer to the surface fossils are found, the younger they are.
Explore More Science Topics
We’ve sent you an email with instructions how to reset your password.
Choose Your Free Trial Period
3 Days

3 days to access to all of our teaching resources for free.

Continue to Lessons
30 Days

Get 30 days free by inviting other teachers to try it too.

Share with Teachers
Get 30 Days Free
By inviting 4 other teachers to try it too.
4 required

*only school emails accepted.

Skip, I will use a 3 day free trial

Thank You!

Enjoy your free 30 days trial