What would you be if your finger bones grew so long that they reached your feet? You'd be a bat!

What if you had no leg bones but kept your arm bones? You'd be a whale, a dolphin, or a porpoise!

This entertaining picture book will keep readers guessing as they learn about how our skeletons are like--and unlike--those of other animals.

"I've been longing for another kind of picture book: one that appeals to young children's wildest imagination in service of real evolutionary thinking....Bone by Bone, by veterinarian and professor Sara Levine, fills the niche to near perfection." --Slate

"engaging and delightfully-illustrated book"--The Guardian