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Take a bite out of the Mesozoic Era

How do we know so much about animals that no longer live on Earth? Paleontologists dig up and analyze ancient bones, other fossils and rocks from long ago to discover what life was once like on our planet.

Tyrannosaurus Rex skull

About nine million years ago, volcanoes still rumbled in Berkeley and mastodon herds thrived in Contra Costa County. Our full fossil cast was made from a mastodon excavated from Mt. Diablo’s southern slope. Could you have mastered a mastodon? See how a mastodon’s skeleton shaped its massive body.

Would you have been a dinosaur’s dinner? Come face-to-crushing teeth with a T. rex skull. The bite force of the T. rex was 3,000 pounds, and looking at this skull you can see why. Our Tyrannosaurus rex fossil skull was cast from a real skull discovered at the Cretaceous Hell Creek formation in Montana.


How big was a Triceratops’ horn? Visit a model paleontology dig where a Triceratops horned head is revealed in ancient rock. This real skull comes from a three-horned Triceratops. See it in preparation to be dug out, but not fully excavated, and get an up-close view of what it’s like to be a paleontologist in the field.

What stories do these fossil finds tell us about Earth long ago, and today?