Dinosaurs lived on Earth for about 175 million years, until they were entirely wiped out by the K-T extinction event at the end of the Cretaceous Period. They lived during the Mesozoic Era, and examples of dinosaurs can be found in all three periods of that era. read more
Non-bird dinosaurs lived between about 245 and 66 million years ago, in a time known as the Mesozoic Era. This was many millions of years before the first modern humans, Homo sapiens, appeared. Scientists divide the Mesozoic Era into three periods: the Triassic, Jurassic and Cretaceous. read more
The fossil record shows that dinos lived alongside comparable groups of reptiles for millions of years without overtaking them. For example, the early dinosaurs were contemporaries of crurotarsans, croc ancestors, during the late Triassic period about 230 to 200 million years ago. read more