The Mesozoic Era is the second era in the Phanerozoic Eon, and is one of three, the two other eras being the Paleozoic (which came before) and the Cenozoic (which came after).
… This is why it is called the Mesozoic, which is Greek for "middle life." The Mesozoic lasted from approximately 250 to 65 million years ago, and is subdivided into three geologic periods: the Triassic, Jurassic, and Cretaceous. The era began after the Permian-Triassic mass extinction and ended with the Cretaceous-Paleogene mass extinction. The Mesozoic is perhaps best known for being the "age of the dinosaurs," the era in which dinosaurs arose and came to dominate the Earth. Flowering plants also appeared towards the end of this era. At this time mammals and birds first evolved, but would not diversify that much until the Cenozoic Era. The Mesozoic was much warmer, and the supercontinent of Pangea separated and was drifting apart to form the modern continents. (MORE) 
