page_title: Dinosaur
section_title: Taxonomy
hierarchical_section_title: Dinosaur / Classification / Taxonomy
caption_attribution_description: English: Camarasaurus, Brachiosaurus, Giraffatitan, Euhelopus. Cropped and enhanced version of the image located here: [1]. Also removed Cyrillic Russian-language labels. Killdevil (talk) 14:57, 12 December 2008 (UTC)
context_page_description: 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, although the exact origin and timing of the evolution of dinosaurs is the subject of active research. They became the dominant terrestrial vertebrates after the Triassic–Jurassic extinction event 201.3 million years ago; their dominance continued throughout the Jurassic and Cretaceous periods. The fossil record demonstrates that birds are modern feathered dinosaurs, having evolved from earlier theropods during the Late Jurassic epoch. As such, birds were the only dinosaur lineage to survive the Cretaceous–Paleogene extinction event approximately 66 million years ago. Dinosaurs can therefore be divided into avian dinosaurs, or birds; and non-avian dinosaurs, which are all dinosaurs other than birds.
  Dinosaurs are a varied group of animals from taxonomic, morphological and ecological standpoints. Birds, at over 10,000 living species, are the most diverse group of vertebrates besides perciform fish.
context_section_description: The following is a simplified classification of dinosaur groups based on their evolutionary relationships, and organized based on the list of Mesozoic dinosaur species provided by Holtz (2007). A more detailed version can be found at Dinosaur classification.
  The dagger (†) is used to signify groups with no living members.
  Dinosauria
  Saurischia ("lizard-hipped"; includes Theropoda and Sauropodomorpha)
  †Herrerasauria (early bipedal carnivores)
  Theropoda (all bipedal; most were carnivorous)
  †Coelophysoidea (small, early theropods; includes Coelophysis and close relatives)
  †Dilophosauridae (early crested and carnivorous theropods)
  †Ceratosauria (generally elaborately horned, the dominant southern carnivores of the Cretaceous)
  Tetanurae ("stiff tails"; includes most theropods)
  †Megalosauroidea (early group of large carnivores including the semiaquatic spinosaurids)
  †Carnosauria (Allosaurus and close relatives, like Carcharodontosaurus)
  Coelurosauria (feathered theropods, with a range of body sizes and niches)
  †Compsognathidae (common early coelurosaurs with reduced forelimbs)
  †Tyrannosauridae (Tyrannosaurus and close relatives; had reduced forelimbs)
  †Ornithomimosauria ("ostrich-mimics"; mostly toothless; carnivores to possible herbivores)
  †Alvarezsauroidea (small insectivores with reduced forelimbs each bearing one enlarged claw)
  Maniraptora ("hand snatchers"; had long, slender arms and fingers)
  †Therizinosauria (bipedal herbivores with large hand claws and small heads)
  †Oviraptorosauria (mostly toothless; their diet and lifestyle are uncertain)
  †Archaeopterygidae (small, winged theropods or primitive birds)
  †Deinonychosauria (small- to medium-sized; bird-like, with a distinctive toe claw)
  Avialae (modern birds and extinct relatives)
  †Scansoriopterygidae (small primitive avialans with long third fingers)
  †Omnivoropterygidae (large, early short-tailed avialans)
  †Confuciusornithidae (small toothless avialans)
  †Enantiornithes (primitive tree-dwelling, flying avialans)
  Euornithes (advanced flying birds)
  †Yanornithiformes (toothed Cretaceous Chinese birds)
  †Hesperornithes (specialized aquatic diving birds)
  Aves (modern, beaked birds and their extinct relatives)
  †Sauropodomorpha (herbivores with small heads, long necks, long tails)
  †Guaibasauridae (small, primitive, omnivorous sauropodomorphs)
  †Plateosauridae (primitive, strictly bipedal "prosauropods")
  †Riojasauridae (small, primitive sauropodomorphs)
  †Massospondylidae (small, primitive sauropodomorphs)
  †Sauropoda (very large and heavy, usually over 15 m (49 ft) long; quadrupedal)
  †Vulcanodontidae (primitive sauropods with pillar-like limbs)
  †Eusauropoda ("true sauropods")
  †Cetiosauridae ("whale reptiles")
  †Turiasauria (European group of Jurassic and Cretaceous sauropods)
  †Neosauropoda ("new sauropods")
  †Diplodocoidea (skulls and tails elongated; teeth typically narrow and pencil-like)
  †Macronaria (boxy skulls; spoon- or pencil-shaped teeth)
  †Brachiosauridae (long-necked, long-armed macronarians)
  †Titanosauria (diverse; stocky, with wide hips; most common in the Late Cretaceous of southern continents)
  †Ornithischia ("bird-hipped"; diverse bipedal and quadrupedal herbivores)
  †Heterodontosauridae (small basal ornithopod herbivores/omnivores with prominent canine-like teeth)
  †Thyreophora (armored dinosaurs; mostly quadrupeds)
  †Ankylosauria (scutes as primary armor; some had club-like tails)
  †Stegosauria (spikes and plates as primary armor)
  †Neornithischia ("new ornithischians")
  †Ornithopoda (various sizes; bipeds and quadrupeds; evolved a method of chewing using skull flexibility and numerous teeth)
  †Marginocephalia (characterized by a cranial growth)
  †Pachycephalosauria (bipeds with domed or knobby growth on skulls)
  †Ceratopsia (quadrupeds with frills; many also had horns)
caption: Artist's impression of four macronarian sauropods: from left to right Camarasaurus, Brachiosaurus, Giraffatitan, and Euhelopus
exif: {"Image XResolution": "96", "Image YResolution": "96", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "paint.net 4.1.1"}