What on earth was triceratops thinking?

Object of the Month: 04/2013

What is it?:

Triceratops brain endocast and brain case


Age: 70 million years, Late Cretaceous Period
Where was it collected:

Hell Creek Formation, eastern Montana by SMM palenotology crew


What is it made of?:

Endocast is rubber, brain case is fossilized bone


Accession #: P93.16.1

While Triceratops was a huge dinosaur, its brain didn’t quite measure up in size. While dinosaur brains don’t fossilize, we can get a sense of how small they are relative to the rest of its body by making a copy of the space inside their skull bones.

The black object on the right is an endocast, or brain cavity mold, made from the inside of the brain case bone on the left. The endocast isn’t the exact size of Triceratops’ brain,Triceratops brain position: This diagram shows where the triceratops brain was postitioned.
Triceratops brain position: This diagram shows where the triceratops brain was postitioned.Courtesy American Museum of Natural History staff
but it’s pretty close. The actual brain was slightly smaller surrounded by a membrane and fluid.

Why bother to make an endocast? For one, it shows where major nerves proceed out to the dinosaur’s body. It’s also helpful in determining the correct elevation of dinosaurs’ heads.

Want to learn more about dinosaur brains? Click on some of the links below.

Are you feeling creative? Try writing your own label for these objects.

Web links:
Facts and figures on triceratops
Facts and figures about different dinosaur brains
What do we know about the relative intelligence of dinosaurs?

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