When did the dinosaurs first appeared on Earth?
about 10 million years ago
about 70 million years ago
about 230 million years ago
about 600 million years ago
The oldest known findings of dinosaurs are about 230 million years old. Paleontologists think that the early dinosaur genus Eoraptor resembles the common ancestor of all dinosaurs; if this is true, its traits suggest that the first dinosaurs were small, bipedal predators.