A Mysterious Egg — Stacy McAnulty

What if a fossil in your backyard ... came to life?!
 
Frank's grandma is a famous paleontologist (that's a dinosaur scientist). But she's also an adult who makes up rules. Rules like: no digging for dinosaur bones when you have a sunburn. That means Frank is stuck playing inside with his annoying cousin, Samantha. But then Grandma finds a fossil of an egg! And when Frank and Sam sneak into the dino lab late at night, they find something even more amazing....
 
The hilarious Dino Files chapter book series follows a nine-year-old dinosaur expert, his paleontologist grandparents, a cat named Saurus, and fossils that might not be so extinct!