Geronimo Stilton's ancestor, Geronimo Stiltonoot, investigates a witness's claim of a moving mountain of ice.

Dr. Clock and his baby travel back in time to visit prehistoric animals in the Ice Age.

Geronimo and his friends participate in a treasure hunt set up by his rival and are determined to overcome all of its challenging obstacles, including tricky riddles and smelly dinosaurs.

Fifth-grader Ronnie and Ms. Lernin tour the Cenozoic Era, where they encounter three kinds of mammals--monotremes, marsupials, and placental mammals--and other animals with which they shared the Earth.

In their time travel experiment the Dinosaur Explorers find themselves in the Carboniferous and Permian periods and come face-to-face with giant spiders and massive lizards.

Still trying to stop the evil Dr. Kron-Tox, Andrew, his cousin Judy, Thudd the robot, and Beeper find Uncle Al in the Ice Age, where they encounter prehistoric animals, birds, and people.

When Connecticut middle-schooler Jake and his older sister Kady are transported back to Pangaea, the strange world of lost civilizations, they must find the truth behind the mythic Fire Opal Eye in order to survive.

The reader's choices determine whether three friends will survive after being mysteriously transported back in time to when the climate was cold and saber-toothed cats and wooly mammoths roamed the land.

A little girl named Stone lives with her father during prehistoric times where mastodons and ferocious beasts abound. She longs to be as strong as her father. But when he becomes ill, she must journey deep into the wilderness to find a cure. Stone will need bravery for the harrowing journey, but she will need kindness most of all. A tender tale about the bond between a father and daughter, Strong as Stone illustrates that the power of love and compassion...

"Geronimo Stilton's ancient ancestor Geronimo Stiltonoot is back in another prehistoric adventure! It's the night of the big Cavemouse Idol competition, but Geronimo Stiltonoot isn't there. He has a cold, and goes to bed early. So when it's discovered that the contest's valuable grand prize has been stolen, Geronimo is the main suspect! He must prove his innocence ... or he'll end up in enormouse trouble!"--