Cretaceous Period

The  is a period of time that spans seventy-nine million years, from the to the. During this time, flora and fauna alike grew in size and diversified. It is a level in the NES version of Mario's Time Machine, where Bowser travels back in time to about eighty million years ago and steals a Dinosaur Egg, and Mario later travels back in time after taking the Dinosaur Egg back. After Bowser entered the area, it became infested with Koopas and Bodyslam Koopas that try to stop Mario (although there are also regular dinosaurs in the background). Eventually, Mario makes it to a cave (at the far-right of the area), drops off the Dinosaur Egg, and time travels forward to the present.

The good endings for the MS-DOS and SNES versions of Mario's Time Machine also feature the Cretaceous Period. If everything is done correctly, Bowser attempts to use the Timulator to escape Mario, but it malfunctions and sends him back to the Cretaceous Period. Bowser is soon squished by a large dinosaur. In the MS-DOS version, his crushed remains are then thrown away like a flying disc. Exclusively in the MS-DOS version, Mario also ends up here if he enters an incorrect date in the Timulator. He can only escape by catching some falling eggs from a Pterodactyl while Bullet Bills attack him. After catching enough eggs, Yoshi appears, and he hops onto him and travels back to the present.