Stegothesaurus has little in common with his fellow dinosaurs until he meets an allosaurus that seems as hungry for synonyms as he is.

Oona finds a giant egg and brings it back to West Wog to care for it, and see what hatches--but others in the cave want to claim her egg, particularly the nasty kid Bruce Brute, and when the baby stegosaurus hatches it will have to choose who it wants to live with.