Human-dinosaur coexistence

The notion that dinosaurs (as colloquially defined) and humans coexisted at some time in the past or still coexist in the present, although completely rejected by modern mainstream science, is common among Young Earth creationists and other similar groups.

Mainstream science currently understands that all birds are dinosaurs that descended from feathered theropods. By this broad and more technical sense of the word, humanity has coexisted with dinosaurs since the first humans appeared on Earth. However, in a narrow and more colloquial sense, the term "dinosaur" refers specifically to non-avian dinosaurs, which, still according to this mainstream vision, all died out about 66 million years ago in the Cretaceous–Paleogene extinction, caused by a comet or asteroid impact, while the genus Homo emerged only about 2 to 3 million years ago, leaving a period of tens of millions of years between the last dinosaurs and the first humans.

To Young Earth creationists, who believe the Earth is no older than 6,000 years old, the ideas that birds descend from dinosaurs and that dinosaurs were already long extinct when humans first appeared are both wrong. They believe that dinosaurs coexisted with humans and assert that this is evidenced by both visual and textual depictions. For example, they say that the Behemoth described in the Bible, as well as dragons, are actually historical names for dinosaurs.