Palaeos		Ornithischia
Vertebrates		Classification

Ornithischia Classification

DINOSAUROMORPHA
|--+--THEROPODA
|  `--SAUROPODOMORPHA
|
ORNITHISCHIA
|--Fabrosauridae
`--+--Thyreophora
   |  |--Stegosauria
   |  `--Ankylosauria
   `--Cerapoda
       |--Ornithopoda
       |  |==Hypsilophodontidae
       |  `--Hadrosauridae
       `--+--Heterodontosauridae
          `--Marginocephalia
             |--Pachycephalosauria
             `--Ceratopsia

Order Ornithischia

Traditional classification

The following is based mainly on Carroll (1988), as the most recent comprehensive linnaean classification of the Vertebrates, with more recent groups added. Each taxon is listed by rank, name, and original author, and followed by a short description. Some additions have also been made from Paul 2010 and Holtz 2011. Linnaean names may not match their cladistic equivalents. New taxa are indicated by inverted commas. MAK120308 120312

Infraclass Archosauromorpha Huene, 1946 (cont.)
  Holoorder Ornithischia Seeley, 1888 "bird-hipped" dinosaurs
   Suborder Ornithopoda Marsh, 1881 generalised bipedal, herbivorous dinosaurs, mostly a "wastebasket taxon" for anything taht doesn't fit in the other groups. L Trias to L Cret, Cosm.
     Family Pisanosauridae Casamiquela, 1967 the most primitive group of ornithischians, monospecies only, L Tr of S Am
     Family Fabrosauridae Galton, 1972 small bipedal generalised ancestral ornithischians, E Jur to M Jur of S Afr, EAs.[1]
     Family Heterodontosauridae Romer, 1966 small bipedal early specialised forms, E Jur to E Cret of S Afr, Eur, EAs.
     Family Hypsilophodontidae Dollo, 1882 small bipedal, cursorial, generalised ornithopods, ancestral to later groups, M Jur to L Cret. Cosm.[2]
     Families not specified - a number of iconic types such as Muttaburrasaurus ( M Cret of Aus) and Tenontosaurus (M Cret of N Am) that don't fit easily into the established groups, perhaps require monospecific families or subfamilies
     Family Rhabdodontidae medium-sized ornithopods that represnet a distinct evolutionary line - L Cret of Eur
     Family Dryosauridae small to medium sized, bipedal, cursorial, ornithopods, intermediate between hypsilophodonts and iguanodonts, Monogeneric. L Jur of E Afr, N Am.
     Family Iguanodontidae Cope, 1869 large to very large, bipedal and faculatively quadrapedal, ornithopods, intermediate between dryosaurs and hadrosaurs. L Jur to L Cret, Eur, N Am, As.
     Family Hadrosauridae "duck-billed" dinosaurs, large to very large, bipedal and faculatively quadrapedal, ornithopods, highly specialsed dental batteries, frequently with head crests. E to L Cret, N Am, As, Eur, SAm.
      Subfamilies not specified - a large assortment of various primitive and unspecialised Hadrosaurus, E to L Cret, N Am, As, Eur, SAm.
      Subfamily Saurolophinae - flat-headed, broad-Snouted hadrosaurs - L Cret of N Am & E As
       Tribe Maiasaurini—unspecialised, primitive, broad-snouted duckbilled dinosaurs - L Cret of N Am
       Tribe Saurolophini—spike-crested duckbilled dinosaurs - L Cret of N Am & E As
       Tribe Edmontosaurini— very broad-snouted (classic "duck bill" dinosaurs - L Cret of N Am & E As
nbsp;     Subfamily Lambeosaurinae - crested hadrosaurs - L Cret of N Am
       Tribe Saurolophini - tube crested lambeosaurines
       Tribe Corythosaurini (=Lambeosaurini) - helmet crested lambeosaurines
   Suborder unspecified[3]
     Family Scelidosauridae Cope, 1869 - Ancestral armoured types - mostly Early Jurassic. Quadrupedal, ancestral armoured dinosaurs. Includes light running forms and large heavily armed types. Length 1 to 4.5 meters E Jur of Eur, NAm, As
   Suborder Stegosauria Marsh, 1877 - Plated dinosaurs - spines along the back and tail for protection, plates served a thermoregulatory purpose. Quadrupedal, short forelimbs, slow-moving. Length 3 to 10 meters M Jur to E Cret of N Am, Eur, As, Afr
     Family Huayangosauridae - Primitive plated dinosaurs; M Jur of E As
     Family Stegosauridae Marsh, 1877 advanced plated dinosaurs; M Jur to E Cret of N Am, Eur, As, Afr
      Subfamily Kentrosaurinae - small plates, shoulder spines, spikes along back and tail - usually given family rank (Kentrosauridae); may be monotypic - L Jur of Afr, ?Eur
      Subfamily Dacentrurinae - tail spikes like Stegosaurus, otherwise resembles Kentrosaurus L Jura of Eur
      Subfamily Stegosaurines - advanced stegosaurs, alternatinbg paired plates, no shoulder spines; L Jur to E Cret of NAm & EAs
   Suborder Ankylosauria Osborn, 1923 heavily armoured dinosaurs, 2 to 10 meters long, quadrupedal, slow moving, and fed on soft vegetation.
     Family Polocanthidae - ancestral ankylosaurs - L Jur to L Cret of Eur, N Am, EAs & Ant.
     Family Nodosauridae Marsh, 1890 - with spikes on the shoulders - E to L Cret of Eur & N Am
     Family Ankylosauridae Brown, 1908 - with a war club at the end of the tail - E to L Cret of E As & N Am
   Suborder Pachycephalosauria Sternberg, 1945 (Only one family; Homalocephalidae Dong, 1974 is comprised of juvenile pachycephalosaurids only)
     Family Pachycephalosauridae Sternberg, 1945 dome headed dinosaurs, superficially resemble the ornithopods; bipedal, small to medium-sized, with a bony "battering ram" head.  L Cret of NAm & E As
   Suborder Ceratopsia Marsh, 1890 horned dinosaurs, small to large parrot-beaked dinosaurs,
     Family Chaoyangsauridae Zhao, Cheng, & Xu, 1999 ancestral horned dinosaurs (or ancestral marginocephalia?) L Jur of EAs
     Family Psittacosauridae Osborn, 1923 parrot-beaked dinosaurs, stocky animals about about 1.5 meters long, hornless, bipedal and faculatively quadrapedal, E Cret of EAs
     Family Protoceratopsidae Granger & Gregory, 1923 small to medium sized ancestral hornless forms, bipedal or quadrapedal L Cret of EAs & NAm
      Subfamily Leptoceratopsinae - short frilled protoceratopsids - L Cret of E AS & N Am
      Subfamily Bagaceratopinae - Small-horned, lump-nosed Frilled Dinosaurs - L Cret of Eur & E As
      Subfamily Protoceratopsinae - advanced, deep-tailed protoceraptopsids - L Cret of E As
     Family Ceratopsidae Marsh, 1890 large to gigantic horned dinosaurs, quadrapedal, rhino-like L Cret of NAm
      Subfamily Centrosaurinae - short-frilled horned dinosaurs
      Subfamily Chasmosaurinae - long-frilled horned dinosaurs

Hybrid classification

This section is part of a discontinued and impractical attempt to integrate the rank-based Linnaean and the phylogeny-based Cladistic systems . We have distinguished between monophyletic and paraphyletic taxa (or clades and grades), as indicated by the following key regarding prefixes:

• para- for a paraphyletic (an ancestral or evolutionary grade defined only by shared primitive features and lack of specialised features) according to consensus opinion
• holo- for holophyletic (=monophyletic)
• ambi- for when different cladistic analyses dissagree as to whether a taxon is paraphyletic or monophyletic
• mono- for a monotypal taxon
• evo- for when a taxon is considered monophyletic according to current consensus cladistic studies, but morphologically and/or stratigraphically intermediate and so considered to have given rise to other taxa according to evolutionary systematics or a general gradistic perspective (which implies reversals (loss of original synapomorphies) and a non-parsimony-based phylogeny)

For the phylogenetic arrangement, see the dendrogram page MAK120308 120312

Parainfraclass Archosauromorpha Huene, 1946 (cont.)
  Holoorder Ornithischia Seeley, 1888 "bird-hipped" dinosaurs
   Holosuborder Ornithopoda Marsh, 1881 generalised bipedal, herbivorous dinosaurs, mostly a "wastebasket taxon" for anything taht doesn't fit in the other groups. L Trias to L Cret, Cosm.
     Monofamily Pisanosauridae Casamiquela, 1967 the most primitive group of ornithischians, monospecies only, L Tr of S Am
     Parafamily Fabrosauridae Galton, 1972 small bipedal generalised ancestral ornithischians, E Jur to M Jur of S Afr, EAs.
     Holofamily Heterodontosauridae Romer, 1966 small bipedal early specialised forms, E Jur to E Cret of S Afr, Eur, EAs.
     Parafamily Hypsilophodontidae Dollo, 1882 small bipedal, cursorial, generalised ornithopods, ancestral to later groups, M Jur to L Cret. Cosm.
     Families not specified - a number of iconic types such as Muttaburrasaurus ( M Cret of Aus) and Tenontosaurus (M Cret of N Am) that don't fit easily into the established groups, perhaps require monospecific families or subfamilies
     Holofamily Rhabdodontidae medium-sized ornithopods that represnet a distinct evolutionary line - L Cret of Eur
     Evofamily Dryosauridae small to medium sized, bipedal, cursorial, ornithopods, intermediate between hypsilophodonts and iguanodonts, Monogeneric. L Jur of E Afr, N Am.
     Parafamily Iguanodontidae Cope, 1869 large to very large, bipedal and faculatively quadrapedal, ornithopods, intermediate between dryosaurs and hadrosaurs. L Jur to L Cret, Eur, N Am, As.
     Holofamily Hadrosauridae "duck-billed" dinosaurs, large to very large, bipedal and faculatively quadrapedal, ornithopods, highly specialsed dental batteries, frequently with head crests. E to L Cret, N Am, As, Eur, SAm.
      Subfamilies not specified - a large assortment of various primitive and unspecialised Hadrosaurus, E to L Cret, N Am, As, Eur, SAm.
      Holosubfamily Saurolophinae - flat-headed, broad-Snouted hadrosaurs - L Cret of N Am & E As
       Ambitribe Maiasaurini—unspecialised, primitive, broad-snouted duckbilled dinosaurs - L Cret of N Am
       Ambitribe Saurolophini—spike-crested duckbilled dinosaurs - L Cret of N Am & E As
       Ambitribe Edmontosaurini— very broad-snouted (classic "duck bill" dinosaurs - L Cret of N Am & E As
nbsp;     Holosubfamily Lambeosaurinae - crested hadrosaurs - L Cret of N Am
       Ambitribe Parasaurolophini - tube crested lambeosaurines
       Ambitribe Corythosaurini (=Lambeosaurini) - helmet crested lambeosaurines
   Suborder unspecified
     Evofamily Scelidosauridae Cope, 1869 - Ancestral armoured types - mostly Early Jurassic. Quadrupedal, ancestral armoured dinosaurs. Includes light running forms and large heavily armed types. Length 1 to 4.5 meters E Jur of Eur, NAm, As
   Suborder Stegosauria Marsh, 1877 - Plated dinosaurs - spines along the back and tail for protection, plates served a thermoregulatory purpose. Quadrupedal, short forelimbs, slow-moving. Length 3 to 10 meters M Jur to E Cret of N Am, Eur, As, Afr
     Parafamily Huayangosauridae - Primitive plated dinosaurs; M Jur of E As
     Holofamily Stegosauridae Marsh, 1877 advanced plated dinosaurs; M Jur to E Cret of N Am, Eur, As, Afr
      Monosubfamily Kentrosaurinae - small plates, shoulder spines, spikes along back and tail - usually given family rank (Kentrosauridae); may be monotypic - L Jur of Afr, ?Eur
      Evosubfamily Dacentrurinae - tail spikes like Stegosaurus, otherwise resembles Kentrosaurus L Jura of Eur
      Holosubfamily Stegosaurines - advanced stegosaurs, alternatinbg paired plates, no shoulder spines; L Jur to E Cret of NAm & EAs
   Suborder Ankylosauria Osborn, 1923 - heavily armoured dinosaurs, 2 to 10 meters long, quadrupedal, slow moving, and fed on soft vegetation.
     Evofamily Polocanthidae - ancestral ankylosaurs - L Jur to L Cret of Eur, N Am, EAs & Ant.
     Holofamily Nodosauridae Marsh, 1890 - with spikes on the shoulders - E to L Cret of Eur & N Am
     Holofamily Ankylosauridae Brown, 1908 - with a war club at the end of the tail - E to L Cret of E As & N Am
   Suborder Pachycephalosauria Sternberg, 1945 (Only one family; Homalocephalidae Dong, 1974 is comprised of juvenile pachycephalosaurids only)
     Holofamily Pachycephalosauridae Sternberg, 1945 dome headed dinosaurs, superficially resemble the ornithopods; bipedal, small to medium-sized, with a bony "battering ram" head.  L Cret of NAm & E As
   Suborder Ceratopsia Marsh, 1890 horned dinosaurs, small to large parrot-beaked dinosaurs,
     Evofamily Chaoyangsauridae Zhao, Cheng, & Xu, 1999 ancestral horned dinosaurs (or ancestral marginocephalia?) L Jur of EAs
     Evofamily Psittacosauridae Osborn, 1923 parrot-beaked dinosaurs, stocky animals about about 1.5 meters long, hornless, bipedal and faculatively quadrapedal, E Cret of EAs
     Evofamily Protoceratopsidae Granger & Gregory, 1923 small to medium sized ancestral hornless forms, bipedal or quadrapedal L Cret of EAs & NAm
      Evosubfamily Leptoceratopsinae - short frilled protoceratopsids - L Cret of E AS & N Am
      Evosubfamily Bagaceratopinae - Small-horned, lump-nosed Frilled Dinosaurs - L Cret of Eur & E As
      Evosubfamily Protoceratopsinae - advanced, deep-tailed protoceraptopsids - L Cret of E As
     Holofamily Ceratopsidae Marsh, 1890 large to gigantic horned dinosaurs, quadrapedal, rhino-like L Cret of NAm
      Holosubfamily Centrosaurinae - short-frilled horned dinosaurs
      Holosubfamily Chasmosaurinae - long-frilled horned dinosaurs

Notes

[1] either a wastebasket taxon for any really primitive ornithischians (apart from Pisanosaurus) or limited to one or two Early Jurassic species from southern Africa. if the former, the boundaries between the the Fabrosauridae and other stem groups such as the Scelidosauridae and the Hypsilophodontidae are very poorly defined

[2] another ancestral/generalised/wastebasket taxon; generally, all ornithopods beneath the level of dryosaurs. Like other paraphyletic (ancestral) taxa, hypsilophodonts are defined in terms of shared primitive features (plesiomorphies)

[3] Essentially, basal Thyreophora. Although monophyletic Thyreophora and Cerapoda are sometimes given subordinal rank, we have followed Carroll (1988) in retaining the five classic ornithischian suborders

Links: The major dinosaur families at Enchanted Learning; Taxon tree; Linnean Ornithischia, dinosaur mailing list