Three Horns and a Frill

For grown-ups

Through the museum door to a Cretaceous river, where two Triceratops shove and a small one with backwards horns turns up.

What your child practises

• Comparing a young animal with a grown one
• Noticing what changes as something grows
• Looking twice before deciding what something is
• Telling a friend kindly that they have it wrong

Listen for

Your child saying the small one was young, not a new kind, or that its horns would turn round as it grew.

Your part

• Ask the tip on each page, and wait for an answer
• When your child chooses, ask what they hope to see

Take it off the screen

Put a baby photo of your child beside one from today. What changed, and what stayed the same?

Where the facts come from

• Natural History Museum: Triceratops
• Natural History Museum: Ankylosaurus
• Live Science: Surprising twists found in Triceratops horns
• UC Berkeley News: The smallest Triceratops skull
• National Geographic: Old wounds show that Triceratops used its horns for combat

The Fossil Door

Book 3 in this series

• Book 1: The Runaway Egg
• Book 2: The Longest Neck
• Book 3: Three Horns and a Frill (this book)

The old door is waiting at the back of the museum. Next to it stands a giant stone skull with three horns. "That's who we might meet today," says Dr. Okafor. She turns the brass key. Clunk. "Head home at the third bell. One true thing. And never touch a dinosaur."

Click, click, click. The dial turns. "Jurassic!" shouts their Pet. "Jurassic! Jurassic!" The dial stops. It says Cretaceous. "Cre-ta-what?" asks their Pet. "Cretaceous," laughs Dr. Okafor. "Sixty-seven million years ago."

Your child's name steps through the door into warm, wet air. A wide green plain stretches away, with a slow river winding through it. It smells of mud and leaves. Then, from down by the river, comes a noise. CLONK! "What was that?" whispers their Pet.

Two big Triceratops lower their heads. Their horns lock together. Push! Push! It is a shoving match, like two goats. Mud splashes up, higher than your child's name's head. "Are they fighting?" asks their Pet.

Then, just like that, they stop. They stand side by side and snip the plants with their sharp beaks. Snip, snip. "They've stopped pushing," says your child's name. "Now they're eating as if nothing happened!" "Where should we watch from?" asks their Pet. "I want to see everything."