251 million years ago, the Mesozoic Era began. It ended the Paleozoic Era, the age of sea life and marine animals. The Mesozoic Era has been split into three periods. The first period, called the Triassic period, was about 51 million years long. Although dinosaurs and mammals started to appear, they were smaller than the kind of dinosaurs you would think of (such as Tyrannosaurus Rex). Since there was sea life, as the Mesozoic Era began, some species survived the mass extinction. There were very few but some examples are turtles, frogs, and fish. Later, as much as 35 percent of those reptiles died out, which ended the Triassic Period.
The Jurassic period is probably one of the more famous periods in our history because it was the reign of
The Jurassic period is probably one of the more famous periods in our history because it was the reign of