Judy Moody and Friends-Searching for Stinkodon by Megan McDonald illustrated by Erwin Madrid*

Stink is resolved to find a tooth from a saber-toothed tiger in his backyard.  He spends his summer days digging holes in the Moody's backyard.  Judy and his friend Sophie miss his companionship, so they decide to plant a tooth in one of his holes.  In the end everyone is surprised and satisfied.
I love this series for transitional readers. 
Full page illustrations and short chapters.
*Highly recommend.
-Borrowed from the library.