Where did dinosaurs come from？

Where did dinosaurs come from? That apparently simple question has been the subject of intense debate amongst scientists for over 150 years.

Some evolutionists speculate that reptiles, including dinosaurs, evolved from the amphibians,while the amphibians developed from the fish.

It is believed that the Age of the Reptiles began during the Triassic period, approximately 225 million years. Certain tetropods that are thought to have lived in the late Permian/early Triassic (like gorgonopsians, the shovel Lizard Lystrosaurus, and Massetognathus) are supposed to have branched into both small rodent-like mammals and dinosaurs.

The predecessors of dinosaurs are often vaguely described as the “Archosaurs of the Triassic.”  But the truth is that there is no consensus on this. “But paleontologists are equally concerned with puzzling out how these mighty beasts got their start. Who were their ancestors?  Tracing the origins of the earliest dinosaurs has been a major challenge for paleontologists because there are no uncontested fossils from their earliest days on Earth.