Although the word dinosaur means "terrible lizard",the name is somewhat misleading,as dinosaurs are not lizards.Instead,they represent a separate group of reptiles that, like many extinct forms,did not exhibit characteristics traditionally seen as reptilian,such as a sprawling limb posture or ectothermy. Additionally, many prehistoric animals, including mosasaurs,ichthyosaurs, pterosaurs, plesiosaurs, and Dimetrodon, are popularly conceived of as dinosaurs, but are not taxonomically classified as dinosaurs. Through the first half of the 20th century, before birds were recognized to be dinosaurs, most of the scientific community believed dinosaurs to have been sluggish and cold-blooded.Most research conducted since the 1970s,however, has indicated that all dinosaurs were active animals with elevated metabolisms and numerous adaptations for social interaction.

Since the first dinosaur fossils were recognized in the early 19th century,mounted fossil dinosaur skeletons have been major attractions at museums around the world, and dinosaurs have become an enduring part of world culture. The large sizes of some groups,as well as their seemingly monstrous and fantastic nature, have ensured dinosaurs' regular appearance in best-selling books and films, such as Jurassic Park. Persistent public enthusiasm for the animals has resulted in significant funding for dinosaur science,and new discoveries are regularly covered by the media.