Dinosaurs roamed Earth for such a long period of time that dinosaur fossils existed while dinosaurs were still alive.
It was in this environment that the reptiles known as dinosaurs first evolved.
Reptiles tend to flourish in hot climates because their skin is less porous than, for example, mammal skin, so it loses less water in the heat. Reptile kidneys are also better at conserving water.
Toward the end of the Triassic, a series of earthquakes and massive volcanic eruptions caused Pangaea to slowly begin to break into two. This was the birth of the North Atlantic Ocean
Source: nhm.ac.uk
