Why Did T. rex Have Short Arms?: And Other Questions about Dinosaurs (Good Question!) is a great book! I love learning about things I never knew and I had no idea why T.rex had short arms.
This book asks all the important questions:
When did the first dinosaurs appear on Earth?
What happened to them 65 million years ago?
How do we know about dinosaurs—and are there any still alive today?
Dinosaurs are absolutely irresistible and your kids will love this book. You will love it too and probably learn a thing or two about dinosaurs.