Derek Miller 
Shells, Scales, and Skin [PDF ebook] 

What’s the difference between skin and scales? Why do some animals live inside a hard shell? Early readers will learn about the diverse body coverings that allow animals to survive in their various environments, from the jungle to the ocean. Using simple language and close text-to-image correlation, this book introduces children to the fascinating ways animals’ bodies have evolved to thrive in different parts of the world.