Dinosaurs were the dominant vertebrate animals for over 160 million years, from the late Triassic period when most of them became extinct in the Cretaceous Tertiary extinction event. The 10,000 living species of birds have also been classified as dinosaurs, apprently.

The word dinosaur, which means “terrible lizard,” was coined in 1842, but now we realize that they are not actually lizards, although their appearnace do resemble to each other.
Dinosaurs were the largest land animals of all time, though a large number of dinosaurs are apprently smaller than a turkey in size. 

Dinosaurs as a group got bigger over time until an extinction event 65 million years ago wiped out all but bird-like dinosaurs. Scientists don’t agree entirely on what happened, but the extinction likely to involve impact of meteors and astroids, choking chemicals from erupting volcanoes, climate change and possibly other factors.

Many people may ask why such smaller creature such as fish and snakes have survived that period, scientist beleived that dinosaurs where too big and reckless to avoid salvation; wheareas fish could hide in water and snakes could hide in narrow space between objects.