Did you know that therer were many reptiles that roamed the land, sea, and air at the time of the dinosaurs that were not dinosaurs? It’s a fact! Marine reptiles are not dinosaurs, pterasaurs are not dinosaurs, and there were many giant reptiles that lived before the dinosaurs that are not coinsidered dinosaurs.
Well, how do we know what is and what isn’t a dinosaur?
An animal must meet the following criteria to be a dinosaur:
- Dinosaurs had a hole between the eye socket and nostril.
- Dinosaurs had a complete hole in the hip socket.
- Dinosaurs have 3 main toes, and three main fingers
The main thing that seperates dinosaurs from other reptiles, though, is the stance. Because of the hole in their hip socket, dinosaurs have an upright stance, instead of a sprawling stance, like am iguana or an alligator.
You can find out about a lot of interesting non-dinosaurs that lived a long time ago here.