Dinosaurs lived during the Mesozoic era.

 

Dinosaurs lived during the Mesozoic era.

The Mesozoic era roughly ran from 245 to 66 million years ago and is generally divided into three time periods: the Triassic, Jurassic, and Cretaceous periods.

Dinosaurs first evolved during the Triassic period, increased in number and variety in the Jurassic period, evolved even further during the Cretaceous period, and then, well, pretty much just died off really.

Earth’s climate during the Mesozoic Era was generally warm, and there was less difference in temperature between equatorial and polar latitudes than there is today. The Mesozoic was a time of geologic and biological transition. During this era the continents began to move into their present-day configurations. A distinct modernization of life-forms occurred, partly because of the demise of many earlier types of organisms. Three of the five largest mass extinctions in Earth history are associated with the Mesozoic: a mass extinction occurred at the boundary between the Mesozoic and the preceding Paleozoic; another occurred within the Mesozoic at the end of the Triassic Period; and a third occurred at the boundary between the Mesozoic and subsequent Cenozoic, resulting in the demise of the dinosaurs.