Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233. 23 million years ago. The fossil record shows that birds are modern feathered dinosaurs, having evolved from earlier theropods during the Late Jurassic epoch. Other prehistoric animals, including pterosaurs, mosasaurs, ichthyosaurs, plesiosaurs, and Dimetrodon, are not taxonomically classified as dinosaurs.
About Dinosaur in brief
Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233. 23 million years ago. The fossil record shows that birds are modern feathered dinosaurs, having evolved from earlier theropods during the Late Jurassic epoch. Other prehistoric animals, including pterosaurs, mosasaurs, ichthyosaurs, plesiosaurs, and Dimetrodon, while often popularly conceived as dinosaurs, are not taxonomically classified as dinosaurs. The taxon ‘Dinosauria’ was formally named in 1841 by paleontologist Sir Richard Owen, who used it to refer to the \”distinct tribe or sub-order of Saurian Reptiles\” that were then being recognized in England and around the world. The term is derived from Ancient Greek ‘terrible, potent or fearfully great’, and ‘lizard or reptile’, but is also used to evoke their size and majesty. It has also been suggested that Dinosauria be defined with respect to the MRCA Dinosauria, and all its descendants, as Ornithosauria, Ornithodontia, Triceratops and modern birds. Both definitions are common in the same set of animals being defined as dinosaurs: Ornithosaurus = Ornithodon, Iguanodon and Iguanosaurus, and Ornithoidea = Megaguirus. The other dinosaurs mentioned are, like dinosaurs, members of the Sauropsida, except Dimetrosauria. The other members of pterosaurida, like dinosaurs and pterodons, are usually defined as the most recent ancestor of modern birds, and are usually called Ornithosaurs nomenclature nclomenic n.
Dinosaurs are represented on every continent by both extant species and fossil remains. Using fossil evidence, paleontologists have identified over 500 distinct genera and more than 1,000 different species of non-avian dinosaurs. Many dinosaurs were quite small: Xixianykus, for example, was only about 50 centimeters long. While the dinosaurs’ modern-day surviving avian lineage are generally small due to the constraints of flight, many prehistoric dinosaurs were large-bodied. The largest sauropod dinosaurs are estimated to have reached lengths of 39. 7 meters and heights of 18 m and were the largest land animals of all time. Some extinct groups developed skeletal modifications such as bony armor and spines. The large sizes of some dinosaur 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. The idea that non- avian dinosaurs were uniformly gigantic is a misconception based in part on preservation bias, as large, sturdy bones are more likely to last until they are fossilized.