The term 'dinosaur' originates from the Greek words deino and sauros, meaning 'terrible' and 'lizard'.

Sir Richard Owen invented the name 'dinosaur' in 1842, to describe an extinct group of terrestrial reptiles that lived during the Mesozoic. At that time, he had only three or four dinosaur skeletons to consider, but many hundreds more have been found since 1842.Dinosaurs show a range of adaptations to a wide range of environments and conditions, and as a result they became the most successful land animals of all time.

Dinosaurs are animals that dominated the terrestrial ecosystem for over 100-million years. Non-avian dinosaurs became extinct 65 million years ago (Mya) at the end of the Cretaceous period. Dinosaurs are known from both fossils and nonfossils including fossilized bones, feces, trackways, gastroliths, feathers, impressions of skin and internal organs, and "soft tissues, including blood vessels and cells lining them. Since the first dinosaur was recognized in the 19th century, their mounted There are many misconception about what the dinosaurs were. Dinosaurs were reptiles (horny or scaly.skinned tetrapods that lay eggs) which lived on land during the Mesozoic Era (250 - 65 million years ago). Dinosaurs arose in the Middle or Late Triassic, some 235-230 million years ago. The large marine reptiles and the flying reptiles of the Mesozoic were not dinosaurs

skeletons have become a major attraction at museums around the world. Dinosaurs have become a part of world culture, and have remained consistently popular, especially among children. They have been featured in bestselling books and blockbuster films like Jurassic Park, and new discoveries are regularly covered by the media. The term is also used informally to describe any prehistoric reptile, like the pelycosaur Dimetrodon, the winged pterosaurs, and the aquatic ichthyosaurs, plesiosaurs, and mosasaurs.

The dinosaurs originated during the Triassic period, some 230 million years ago. It is clear thatdinosaurs are archosaurs. The Archosauria, or 'ruling reptiles arose over 250 million years ago at the end of the Permian period, and they beecame important vcarnivores in the Triassic.