DARREN: Jennifer, can you give me the three sub-classes of the Mesozoic Era?
JENNIFER: Triassic, Jurassic, and Cretaceous … Follow-up – what preceded the Mesozoic Era?
DARREN: Paleozoic.
The Mesozoic Era is the second-last era of Earth’s geological history, lasting from 252 to 66 million years ago, and comprising the Triassic, Jurassic, and Cretaceous periods. It is sometimes called the Age of Reptiles of the Age of Conifers, and is characterised by the dominance of dinosaurs, an abundance of conifers and ferns, a hot greenhouse climate, and the tectonic breakup of the supercontinent Pangaea. The name Mesozoic means “middle life” in ancient Greek.
The Paleozoic Era came before the Mesozoic Era, the earliest of the three eras of geological history, with a name meaning “ancient life”. It was a time of dramatic geological, climatic, and evolutionary change, seeing an explosion of new species emerging, and life beginning in the ocean, but transitioning to the land.
The Annotated Gilmore Girls 