Final answer:
During the Mesozoic period, diapsids diverged into Archosaurs, leading to modern crocodiles, alligators, and birds, as well as extinct creatures like dinosaurs.
Step-by-step explanation:
During the Mesozoic period, diapsids diverged into Archosaurs and Lepidosauromorpha. The Archosauromorpha group includes modern crocodiles, alligators, and the now-extinct ichthyosaurs, pterosaurs, dinosaurs, and birds, with birds having evolved from a branch of maniraptoran theropod dinosaurs. The Lepidosauromorpha, on the other hand, includes modern lizards, snakes, and tuataras.