User:Ohthegreatone/sandbox

Dinosaur

Dinosaurs are a diverse group of animals of the clade Dinosauria that first appeared during the Triassic period. Although the exact origin and timing of the evolution of dinosaurs is the subject of active research,[1] the current scientific consensus places their origin between 231 and 243 million years ago.[2] They became the dominant terrestrial vertebrates after the Triassic–Jurassic extinction event 201 million years ago. Their dominance continued through the Jurassic and Cretaceous periods and ended when the Cretaceous-Paleogene extinction event led to the extinction of most dinosaur groups 66 million years ago.

Until the late 20th century, all groups of dinosaurs were believed to be extinct. The fossil record, however, indicates that birds, which are now termed "avian dinosaurs,"[3] are the modern descendants of feathered dinosaurs,[4] having evolved from theropod ancestors during the Jurassic Period.[5] As such, birds were the only dinosaur lineage to survive the mass extinction event.[6]

Throughout the remainder of this article, the term "dinosaur" is sometimes used generically to refer to the combined group of avian dinosaurs (birds) and non-avian dinosaurs, while at other times it is used to refer to the non-avian dinosaurs specifically, while the avian dinosaurs are sometimes simply referred to as "birds". This article deals primarily with non-avian dinosaurs.

Dinosaurs are a varied group of animals from taxonomic, morphological and ecological standpoints. Birds, at over 10,000 living species,[7] are the most diverse group of vertebrates besides perciform fish.[8] Using fossil evidence, paleontologists have identified over 500 distinct genera[9] and more than 1,000 different species of non-avian dinosaurs.[10]

Dinosaurs are represented on every continent by both extant species and fossil remains.[11] Some are herbivorous, others carnivorous. While dinosaurs were ancestrally bipedal, many extinct groups included quadrupedal species, and some were able to shift between these stances. Elaborate display structures such as horns or crests are common to all dinosaur groups, and some extinct groups developed skeletal modifications such as bony armor and spines. Evidence suggests that egg laying and nest building are additional traits shared by all dinosaurs.

It is said that millions of years ago the cavemen have had many fights with the dinosaurs and it has not been a fight that people would have liked to watch or be involved in. People have said to have found skulls which have got holes in there heads and that suggests they have had aggressive challenge towards the dinosaurs. The dinosaurs had bashes to the sides of the legs where it looks like the cave men had hit them with an object and people want to find out what the objects are. It is believed to have been a club or a rock but nothing is for cirten. Historians are searching around the globe for any sign of backing up our theories of what had happened. We are cirten that the dinosaurs and the cavemen did have a fight.

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 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.