Dinosaurs

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Dinosaurs are vertebrates that range from reptile-like to bird-like. Dinosaurs dominated the terrestrial ecosystem for over 160 million years from around 230 million years ago until 65 million years ago, at the end of the Cretaceous period, when all non-avian dinosaurs became extinct. Dinosaurs still exist today in the line of birds (avian dinosaurs).

Knowledge about dinosaurs comes from both fossil and non-fossil records, including fossilized bones, feces, trackways, gastroliths, feathers, impressions of skin, internal organs and soft tissues. Dinosaur remains have been found on every continent on Earth, including Antarctica. This shows that all land masses were at one time connected in a super continent, called Pangaea, due to the fact that numerous fossils of the same species have been found on completely different continents. Pangaea began to break up during the Triassic period around 230 million years ago.

Since the first dinosaur was recognized in the 19th century, their mounted, fossilized skeletons have become major attractions at museums around the world. Dinosaurs have become a part of world culture and remain consistently popular, especially among children. They have been featured in best-selling books and blockbuster films such as Jurassic Park, and new discoveries are regularly covered by the media. The term is also used informally to describe any prehistoric reptile, such as the pelycosaur Dimetrodon, the winged pterosaurs, and the aquatic ichthyosaurs, plesiosaurs, and mosasaurs, though none of these are dinosaurs.