Dinosaur clades

thumb|alt=montage of four birds|Birds are avian dinosaurs, and phylogenetic taxonomy includes over 11,000 extant species in the group Dinosauria. Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They existed through most of the Mesozoic era, first appearing early in the Triassic period, They became the dominant terrestrial vertebrates after the Triassic–Jurassic extinction event 201.3 mya and their dominance continued throughout the Jurassic and Cretaceous periods. The fossil record shows that birds are feathered dinosaurs, having evolved from earlier theropods during th

Saurischia ( , meaning "reptile-hipped" from the Greek '''' () meaning 'lizard' and '''' () meaning 'hip joint') is one of the two basic divisions of dinosaurs (the other being Ornithischia), classified by their hip structure. Saurischia and Ornithischia were originally called orders by Harry Seeley in 1888, though today most paleontologists classify Saurischia as an unranked clade rather than an order.

thumb|alt=montage of four birds|In the modern fauna, theropods are represented by over 11,000 species of birds, which are a group of [[maniraptoran theropods within the clade Avialae.]]

Ornithischia () is an extinct clade of mainly herbivorous dinosaurs characterized by a pelvic structure superficially similar to that of birds. The name Ornithischia, or "bird-hipped", reflects this similarity and is derived from the Greek stem ' (), meaning "bird", and ' (), meaning "hip". However, as birds are theropod dinosaurs, they are only distantly related to this group.

Sauropoda (), whose members are called sauropods (; from sauro- + -pod; ), is a clade of saurischian ('lizard-hipped') dinosaurs. Sauropods had very long necks, long tails, small heads (relative to the rest of their body), and four thick, pillar-like legs. They are notable for the enormous sizes attained by some species, and the group includes the largest animals to have ever lived on land. Well-known genera include Alamosaurus, Apatosaurus, Argentinosaurus, Brachiosaurus, Brontosaurus, Camarasaurus, Diplodocus, Dreadnoughtus, and Mamenchisaurus.

Sauropodomorpha ( ; from Greek, meaning "lizard-footed forms") is an extinct clade of saurischian dinosaurs that includes the long-necked, herbivorous sauropods and their ancestral relatives. Early, more basal sauropodomorphs (traditionally termed prosauropods) were bipedal, and the earliest show evidence of omnivorous or carnivorous diets. Over time, sauropodomorph evolution resulted in a shift to herbivorous diets, larger body sizes, and quadrupedal locomotion. The sauropods themselves generally grew to very large sizes, had long necks and tails, and became the largest animals to ever walk t

Ankylosauria is a group of herbivorous dinosaurs of the clade Ornithischia. It includes the great majority of dinosaurs with armor in the form of bony osteoderms, similar to turtles. Ankylosaurs were bulky quadrupeds, with short, powerful limbs. They are known to have first appeared in North Africa during the Middle Jurassic, and persisted until the end of the Late Cretaceous. The two main families of ankylosaurians, Nodosauridae and Ankylosauridae primarily originated from the Northern Hemisphere (North America, Europe and Asia). The more basal Parankylosauria originated from southern Gondwan

Ceratopsia or Ceratopia ( or ; Greek: "horned faces") is a group of herbivorous, beaked dinosaurs that thrived in what are now North America, Asia and Europe, during the Cretaceous Period, although ancestral forms lived earlier, in the Late Jurassic of Asia. The earliest known ceratopsian, Yinlong downsi, lived between 161.2 and 155.7 million years ago. The last ceratopsian species, Triceratops prorsus, became extinct during the Cretaceous–Paleogene extinction event, .

Stegosauria is a group of herbivorous ornithischian dinosaurs that lived during the Jurassic and early Cretaceous periods. Stegosaurian fossils have been found mostly in the Northern Hemisphere (North America, Europe and Asia), Africa and South America. Although their geographical origins are unclear, the earliest unequivocal stegosaurians are known from the Middle Jurassic (Bajocian-Bathonian stages), including Adratiklit, Bashanosaurus, Isaberrysaura and Thyreosaurus.

Thyreophora ("shield bearers"), often known simply as armored dinosaurs is a group of armored ornithischian dinosaurs that lived from the Early Jurassic until the end of the Cretaceous.

Ornithopoda () is a clade of ornithischian dinosaurs, called ornithopods (). They represent one of the most successful groups of herbivorous dinosaurs during the Cretaceous. The most primitive members of the group were bipedal and relatively small-sized, while advanced members of the subgroup Iguanodontia became quadrupedal and developed large body size. Their major evolutionary advantage was the progressive development of a chewing apparatus that became the most sophisticated ever developed by a non-avian dinosaur, rivaling that of modern mammals such as the domestic cow. They reached their a

Coelurosauria from Greek κοῖλος (koîlos, "hollow") + οὐρά (ourá, "tail") + σαύρα (saúra, "lizard") + -ia, meaning "hollow-tailed lizards", is the clade containing all theropod dinosaurs more closely related to birds than to carnosaurs.

Ceratosaurs are members of the clade Ceratosauria, a group of dinosaurs defined as all theropods sharing a more recent common ancestor with Ceratosaurus than with birds. The oldest known ceratosaur, Saltriovenator, dates to the earliest part of the Jurassic, around 199 million years ago. Ceratosauria includes three major clades: Ceratosauridae, Noasauridae, and Abelisauridae, found primarily (though not exclusively) in the Southern Hemisphere. Originally, Ceratosauria included the above dinosaurs plus the Late Triassic to Early Jurassic Coelophysoidea and Dilophosauridae, implying a much earli

Tetanurae (; meaning "stiff tails") is a clade that includes most theropod dinosaurs, including megalosauroids, allosauroids, and coelurosaurs (which includes tyrannosauroids, ornithomimosaurs, compsognathids and maniraptorans, the latter including living birds). Tetanurans are defined as all theropods more closely related to modern birds than to Ceratosaurus and contain the majority of predatory dinosaur diversity. Tetanurae likely diverged from its sister group, Ceratosauria, during the late Triassic. Tetanurae first appeared in the fossil record by the Early Jurassic about 190 mya and by th

Maniraptora is a clade of coelurosaurian dinosaurs which includes birds and the non-avian dinosaurs that were more closely related to them than to Ornithomimus velox. It contains the major subgroups Avialae, Dromaeosauridae, Troodontidae, Oviraptorosauria, and Therizinosauria. Ornitholestes and the Alvarezsauroidea are also often included. Together with the next closest sister group, the Ornithomimosauria, Maniraptora comprises the more inclusive clade Maniraptoriformes. Maniraptorans first appear in the fossil record during the Jurassic Period (see Eshanosaurus), and survive today as living b

Pachycephalosauria (; from Greek παχυκεφαλόσαυρος for 'thick headed lizards') is a clade of ornithischian dinosaurs. Along with Ceratopsia, it makes up the clade Marginocephalia. Pachycephalosaurs lived exclusively in the Northern Hemisphere during the Cretaceous period, with all members being found in North America and Asia. They were all bipedal, herbivorous/omnivorous animals with thick skulls. Skulls can be domed, flat, or wedge-shaped depending on the species, and are all heavily ossified. The domes were often surrounded by nodes and/or spikes. Partial skeletons have been found of several

Carnosauria is an extinct group of carnivorous theropod dinosaurs that lived during the Jurassic and Cretaceous periods.

Ornithomimosauria ("bird-mimic lizards") are theropod dinosaurs which bore a superficial resemblance to the modern-day ostrich. They were fast, omnivorous or herbivorous dinosaurs from the Cretaceous Period of Laurasia (now Asia, Europe and North America), as well as possibly Africa. The group first appeared in the Early Cretaceous and persisted until the Late Cretaceous. Primitive members of the group include Nqwebasaurus, Pelecanimimus, Shenzhousaurus, Hexing and Deinocheirus, the arms of which reached 2.4 m (8 feet) in length. More advanced species, members of the family Ornithomi

Titanosaurs (or titanosaurians; members of the group Titanosauria) were a diverse group of sauropod dinosaurs, including genera from every continent. The titanosaurs were the last surviving group of long-necked sauropods, with taxa still thriving at the time of the extinction event at the end of the Cretaceous. This group includes some of the largest land animals known to have ever existed, such as Patagotitan, estimated at long with a mass of , and the comparably sized Argentinosaurus and Puertasaurus from the same region.

Marginocephalia ( Latin: margin-head) is a clade of ornithischian dinosaurs that is characterized by a bony shelf or margin at the back of the skull. These fringes were likely used for display. This clade was officially defined in the PhyloCode by Daniel Madzia and colleagues in 2021 as "the smallest clade containing Ceratops montanus, Pachycephalosaurus wyomingensis, and Triceratops horridus". There are two clades included in Marginocephalia: the thick-skulled Pachycephalosauria and the horned Ceratopsia. All members of Marginocephalia were primarily herbivores (though pachycephalosaurs are s

Oviraptorosaurs ("egg thief lizards") are a group of feathered bipedal maniraptoran dinosaurs from the Cretaceous Period of what are now Asia and North America. They are distinct for their characteristically short, beaked, parrot-like skulls, with or without bony crests atop the head. They ranged in size from Caudipteryx, which was the size of a turkey, to the 8-meter-long, 1.4-ton Gigantoraptor. The group (along with all maniraptoran dinosaurs) is close to the ancestry of birds. Some researchers such as Maryanska et al (2002) and Osmólska et al. (2004) have proposed that they may represent pr

thumb|upright|Birds, members of the paraves, are the only living dinosaurs. Paraves are a widespread group of theropod dinosaurs that originated in the Middle Jurassic period. In addition to the extinct dromaeosaurids, troodontids, anchiornithids, and possibly the scansoriopterygids, the group also contains the avialans, which include diverse extinct taxa as well as the over 11,000 species of living birds.

Macronaria is a clade of sauropod dinosaurs. Macronarians are named after the large diameter of the nasal opening of their skull, known as the external naris, which exceeded the size of the orbit, the skull opening where the eye is located (hence macro- meaning large, and –naria meaning nose). Fossil evidence suggests that macronarian dinosaurs lived from the Middle Jurassic (Bathonian) through the Late Cretaceous (Maastrichtian). Macronarians have been found globally, including discoveries in Argentina, the United States, Portugal, China, and Tanzania. Like other sauropods, they are known to

Neornithischia ("new ornithischians") is a clade of the dinosaur order Ornithischia. It is the sister group of the Thyreophora within the clade Genasauria. Neornithischians are united by having a thicker layer of asymmetrical enamel on the inside of their lower teeth. The teeth wore unevenly with chewing and developed sharp ridges that allowed neornithischians to break down tougher plant food than other dinosaurs.

Neosauropoda is a clade within Dinosauria, coined in 1986 by Argentine paleontologist José Bonaparte and currently described as Saltasaurus loricatus, Diplodocus longus, and all animals directly descended from their most recent common ancestor. The group is composed of two subgroups: Diplodocoidea and Macronaria. Arising in the early Jurassic and persisting until the Cretaceous–Paleogene extinction event, Neosauropoda contains the majority of sauropod genera, including genera such as Apatosaurus, Brachiosaurus, and Diplodocus. It also includes giants such as Argentinosaurus, Patagotitan and Sa

Therizinosaurs (; once called segnosaurs) are an extinct group of large herbivorous theropod dinosaurs whose fossils have been mainly discovered from Cretaceous deposits in Asia and North America. Potential fragmentary remains have also been found in Jurassic deposits of Asia and Europe. Various features of the forelimbs, skull and pelvis unite these finds as both theropods and maniraptorans, making them relatives of birds. The name of the representative genus, Therizinosaurus, is derived from the Greek (, 'to reap' or 'scythe') and (, 'lizard'). The older representative, Segnosaurus, is deriv

Eusauropoda (meaning "true lizard foot") is a derived clade of sauropod dinosaurs. Eusauropods represent the node-based group that includes all descendant sauropods starting with the basal eusauropods of Shunosaurus, and possibly Barapasaurus, and Amygdalodon, but excluding Vulcanodon and Rhoetosaurus. The Eusauropoda was coined in 1995 by Paul Upchurch to create a monophyletic new taxonomic group that would include all sauropods, except for the vulcanodontids.

Lithostrotia is a clade of derived titanosaur sauropods that lived during the Early Cretaceous and Late Cretaceous. The group was defined by Upchurch et al. in 2004 as the most recent common ancestor of Malawisaurus and Saltasaurus and all the descendants of that ancestor. Lithostrotia is derived from the Ancient Greek , meaning "inlaid with stones", referring to the fact that many known lithostrotians are preserved with osteoderms. However, osteoderms are not a distinguishing feature of the group, as the two noted by Unchurch et al. include caudal vertebrae with strongly concave front faces (

Eudromaeosauria (International Phonetic Alphabet|; "true dromaeosaurs") is a subgroup of terrestrial dromaeosaurid theropod dinosaurs. They were small to large-sized predators that flourished during the Cretaceous Period. Eudromaeosaur fossils are known almost exclusively from the northern hemisphere.

Ornithoscelida () is a proposed clade that includes various major groupings of dinosaurs. An order Ornithoscelida was originally proposed by Thomas Henry Huxley but later abandoned in favor of Harry Govier Seeley's division of Dinosauria into Saurischia and Ornithischia. The term was revived in 2017 after a new cladistic analysis by Baron et al.

Ankylopollexia is an extinct clade of ornithischian dinosaurs that lived from the Late Jurassic to the Late Cretaceous. It is a derived clade of iguanodontian ornithopods and contains the subgroup Styracosterna. The name stems from the Greek word, "ankylos", mistakenly taken to mean stiff, fused (in fact the adjective means bent or curved; used of fingers, it can mean hooked), and the Latin word, "pollex", meaning thumb. Originally described in 1986 by Sereno, a most likely synapomorphic feature of a conical thumb spine defines the clade.

Megaraptora is a clade of carnivorous theropod dinosaurs. Its derived members, the Megaraptoridae are noted for their large hand claws and powerfully-built forelimbs, which are usually reduced in size in other large theropods. Although undoubtedly members of the clade Tetanurae, their relationships to others members of this group have been subject to dispute.

Somphospondyli is an extinct clade of titanosauriform sauropods that lived from the Late Jurassic until the end of the Late Cretaceous, comprising all titanosauriforms more closely related to Titanosauria proper than Brachiosauridae. The remains of somphospondylans have been discovered on all continents.

Turiasauria is an unranked clade of eusauropod dinosaurs known from Middle Jurassic to Early Cretaceous deposits in Europe, North America, and Africa.

Elasmaria is a clade of ornithopods known from Cretaceous deposits in the former Gondwana (South America, Antarctica, Australia, and possibly Africa) that contains many bipedal ornithopods that were previously considered "hypsilophodonts".

Lognkosauria is a clade of giant long-necked sauropod dinosaurs within the clade Titanosauria. It includes some of the largest and heaviest dinosaurs known. They lived in South America and Asia during the Late Cretaceous period.

Rhabdodontomorpha is a clade of basal iguanodont dinosaurs. This group was named in 2016 in the context of the description, based on Spanish findings of an early member of the Rhabdodontidae. A cladistic analysis was conducted in which it was found that Muttaburrasaurus was the sister species of the Rhabdodontidae sensu Weishampel. Therefore, Paul-Emile Dieudonné and colleagues defined Rhabdodontomorpha as a node-based clade: the group consisting of the last common ancestor of Rhabdodon priscus and Muttaburrasaurus langdoni, and all its descendants. Within the clade Zalmoxes and Mochlodon are

Colossosauria is a clade of titanosaur sauropods from the latest Early Cretaceous through the Late Cretaceous of South America. The group was originally named by Bernardo González-Riga et al. in 2019 and defined as the "most inclusive clade containing Mendozasaurus neguyelap but not Saltasaurus loricatus or Epachthosaurus sciuttoi". The clade contains different taxa depending on the phylogenetic analysis used, in the defining paper the only subgroups were Rinconsauria and Lognkosauria, but alternate phylogenies published previously had also included various similar titanosaurs such as Aeolosau

Microraptoria (Greek, μίκρος, mīkros: "small"; Latin, raptor: "one who seizes") is a clade of basal dromaeosaurid theropod dinosaurs. Definitive microraptorians lived during the Barremian to Aptian stages of the Early Cretaceous in China. Probable microraptorian ichnotaxon Dromaeosauriformipes was discovered from the Jinju Formation of South Korea, and some fragmentary Late Cretaceous paravian fossils in North America have been described as putative members of this clade. Many are known for long feathers on their legs and may have been semiarboreal powered fliers, some of which were even capab

Rinconsauria is an extinct clade of titanosaurian sauropods known from the late Cretaceous period of Argentina. All members of this clade are fairly small compared to the largest titanosaurs, at less than around long. The membership of Rinconsauria is highly unstable; some phylogenetic analyses find the clade to be restricted to the two genera that define the clade, Rinconsaurus and Muyelensaurus, but over twenty other titanosaur genera have been included in the clade by various analyses.

Hadrosauromorpha is a clade of iguanodontian ornithopods, defined in 2014 by David B. Norman to divide Hadrosauroidea into the basal taxa with compressed manual bones and a pollex, and the derived taxa that lack them. The clade is formally defined in the PhyloCode as "the largest clade containing Hadrosaurus foulkii, but not Probactrosaurus gobiensis". This results in different taxon inclusion depending on the analysis.

Diamantinasauria is an extinct clade of somphospondylan titanosauriform sauropod dinosaurs with close affinities to the Titanosauria, known from the early Late Cretaceous (Cenomanian-Turonian) of South America and Australia. It was named by Poropat and colleagues in 2021, and contains four (or five, depending on the placement of Wintonotitan) genera: Australotitan, Savannasaurus and Diamantinasaurus from the Winton Formation of Queensland, as well as Sarmientosaurus from the Bajo Barreal Formation of Patagonia. The existence of the clade indicates connectivity between Australia and South Ameri

Parankylosauria is a group of armored thyreophoran dinosaurs known from the Cretaceous of South America, Antarctica, and Australia. Most analyses place parankylosaurs as a member of the Ankylosauria, in which case the group would have split from other ankylosaurs during the mid-Jurassic period, despite this being unpreserved in the fossil record. Another analysis has proposed that parankylosaurs are instead a distinct lineage of non-ankylosaurian armored dinosaurs with more ancestral anatomy. Several parankylosaurs are characterized by a distinctive frond-like tail weapon (called a 'macuahuitl

Eutitanosauria is a clade of titanosaurs, encompassing the more derived members of the group and characterized by the absence of the hyposphene-hypantrum articulation and possibly the presence of osteoderms. The group was first named by Sanz and colleagues in 1999, who used it to unite the group of Argyrosaurus, Lirainosaurus, Saltasaurus and the Peiropolis titanosaur. However, this definition was not used as it made the group equivalent to Saltasauridae, so Saldago redefined it in 2003 to be all titanosaurs closer to Saltasaurus than Epachthosaurus. This definition created Eutitanosauria as t

Brachyrostra (meaning "short snouts") is a clade within the theropod dinosaur family Abelisauridae. It includes the famous genera Carnotaurus, Aucasaurus, potentially Abelisaurus as well as their close relatives from the Cretaceous Period of Argentina and Brazil plus Caletodraco from France. The group was first proposed in an analysis conducted by Juan Canale and colleagues in 2008. They found that all South American abelisaurids described up to that point grouped together as a sub-clade of Abelisauridae, which they named based on the relatively unusual shape of their skulls (in comparison wit