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Information about Ornithischia

Ornithischians
Fossil range: Triassic-Cretaceous
Enlarge picture
Ornithischian pelvic structure (left side)

Ornithischian pelvic structure (left side)
Conservation status
Extinct (fossil)
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Sauropsida
Superorder:Dinosauria
Order:Ornithischia
Seeley, 1888
Suborders


Ornithischia or Predentata is an order of beaked, herbivorous dinosaurs. The name ornithischia is derived from the Greek ornitheos (ορνιθειος) meaning 'of a bird' and ischion (ισχιον) meaning 'hip joint'. They are known as the 'bird-hipped' dinosaurs because of their bird-like hip structure, even though birds actually descended from the 'lizard-hipped' dinosaurs (the saurischians). Being herbivores that sometimes lived in herds, they were more numerous than the saurischians. They were prey animals for the theropods and were smaller than the sauropods.

Characteristics

Enlarge picture
Edmontosaurus pelvis (showing ornithischian structure - left side) Oxford University Museum of Natural History
The Dinosauria superorder was divided into the two orders Ornithischia and Saurischia by Harry Seeley in 1887. This division, which has generally been accepted, is based on the evolution of the pelvis into a more bird-like structure (although birds did not descend from these dinosaurs), details in the vertebrae and armor and the possession of a 'predentary' bone. The predentary is an extra bone in the front of the lower jaw, which extends the dentary (the main lower jaw bone). The predentary coincides with the premaxilla in the upper jaw. Together they form a beak-like apparatus used to clip off plant material.

The ornithischian pubis bone points downward and toward the tail (backwards), parallel with the ischium, with a forward-pointing process to support the abdomen. This makes a four-pronged pelvic structure. In contrast to this, the saurischian pubis points downward and towards the head (forwards), as in ancestral lizard types. Ornithischians also had smaller holes in front of their eye sockets (antorbital fenestrae) than saurischians, and a wider, more stable pelvis. A bird-like pubis arrangement, parallel to the vertebral column, independently evolved three times in dinosaur evolution, namely in the ornithischians, the therizinosauroids and in bird-like dromaeosaurids.

Classification

Taxonomy

Linnaean ranks after Benton (2004),

Phylogeny

The ornithischians are divided in the two clades: the first are the Thyreophora and the second the Cerapoda. The Thyreophora include the Stegosauria (like the armored Stegosaurus) and the Ankylosauria (like Ankylosaurus). The Cerapoda include the Marginocephalia (Ceratopsia like the frilled ceratopsidae and Pachycephalosauria) and the Ornithopoda (among which duck-bills (hadrosaurs) such as Edmontosaurus). The Cerapoda are a relatively recent grouping (Sereno, 1986), and may conceivably be identical to (synonymous with) the older group, Ornithopoda: most of these divisions are not true by definition.

Ornithischia?Pisanosaurus `--+-?Fabrosauridae `--GenasauriaThyreophora | |--Scutellosaurus | `--Thyreophoroidea | |--Emausaurus | `--Eurypoda | |--Stegosauria | `--Ankylosauromorpha | |--Scelidosaurus | `--Ankylosauria `--CerapodaStormbergiaAgilisaurusHexinlusaurusHeterodontosauridae `--+--Ornithopoda `--MarginocephaliaPachycephalosauria `--Ceratopsia

(basal Cerapoda after Butler, 2005)

References

  • Butler, R.J. 2005. The 'fabrosaurid' ornithischian dinosaurs of the Upper Elliot Formation (Lower Jurassic) of South Africa and Lesotho. Zoological Journal of the Linnean Society 145(2):175-218.
  • Sereno, P.C. 1986. Phylogeny of the bird-hipped dinosaurs (order Ornithischia). National Geographic Research 2(2):234-256.

External links

The Triassic is a geologic period that extends from about 251 to 199 Ma (million years ago). As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events.
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The Cretaceous Period is one of the major divisions of the geologic timescale, reaching from the end of the Jurassic Period (i.e. from 145.5 ± 4.0 million years ago (Ma)) to the beginning of the Paleocene epoch of the Tertiary Period (about 65.5 ± 0.3 Ma).
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pelvis (pl. pelvises or pelves) is the bony structure located at the base of the spine (properly known as the caudal end). The pelvis incorporates the socket portion of the hip joint for each leg (in bipeds) or hind leg (in quadrupeds).
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conservation status of a species is an indicator of the likelihood of that species continuing to survive either in the present day or the future. Many factors are taken into account when assessing the conservation status of a species: not simply the number remaining, but the
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For other uses of the term, see Fossil (disambiguation)


FOSSIL is a standard for allowing serial communication for telecommunications programs under the DOS operating system.
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Scientific classification or biological classification is a method by which biologists group and categorize species of organisms. Scientific classification also can be called scientific taxonomy, but should be distinguished from folk taxonomy, which lacks scientific basis.
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Chordata
Bateson, 1885

Typical Classes

See below

Chordates (phylum Chordata) are a group of animals that includes the vertebrates, together with several closely related invertebrates.
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Sauropsida*
Goodrich, 1916

Subclasses
  • Anapsida
  • Diapsida
Synonyms
  • Reptilia Laurenti, 1768
Reptiles are tetrapods and amniotes, animals whose embryos are surrounded by an amniotic membrane, and members of the class
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Dinosauria *
Owen, 1842

Orders & Suborders
  • Ornithischia
  • Cerapoda
  • Thyreophora
  • Saurischia

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Harry Govier Seeley (18 February 1839 - 8 January 1909) was a British paleontologist who determined that dinosaurs fell into two great groups, the Saurischians and the Ornithischians, based on the nature of their pelvic bones and joints.
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8th century - 9th century - 10th century
850s  860s  870s  - 880s -  890s  900s  910s
885 886 887 - 888 - 889 890 891

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Subjects:     Archaeology - Architecture -
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Cerapoda
Sereno, 1986

Infraorders
  • Ceratopsia
  • Ornithopoda
  • Pachycephalosauria


Cerapoda is a clade or suborder of the order Ornithischia. They are the sister group of the Thyreophora within the clade Genasauria.
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Thyreophora
Nopcsa, 1915

Infraorders
  • Ankylosauria
  • Stegosauria


The Thyreophora ("shield bearers", often known simply as "armored dinosaurs" - Greek: θυρεος
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order (Latin: ordo, plural ordines) is a rank between class and family (termed a taxon at that rank). The superorder is a rank between class and order. Exact details of formal nomenclature depend on the Nomenclature Code which applies.
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Herbivory is a form of predation in which an organism known as an herbivore, consumes principally autotrophs[1] such as plants, algae and photosynthesizing bacteria.
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Dinosauria *
Owen, 1842

Orders & Suborders
  • Ornithischia
  • Cerapoda
  • Thyreophora
  • Saurischia

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Ancient Greek refers to the second stage in the history of the Greek language[1] as it existed during the Archaic (9th–6th centuries BC) and Classical (5th–4th centuries BC) periods in Greece.
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hip is the bony projection of the femur which is known as the greater trochanter, and the overlying muscle and fat. The hip joint is the joint between the femur and acetabulum of the pelvis and its primary function is to support the weight of the body in both static
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Aves
Linnaeus, 1758

Orders

About two dozen - see section below

Birds (class Aves) are bipedal, warm-blooded, egg-laying vertebrate animals.
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Saurischia
Seeley, 1887

Suborders
  • Theropoda
  • Sauropodomorpha


Saurischia (from the Greek sauros (σαυρος) meaning 'lizard' and ischion (
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Theropoda
Marsh, 1881

Infraorders
  • Carnosauria
  • Ceratosauria
  • Deinonychosauria
  • Ornithomimosauria
  • Oviraptorosauria


Theropods ('beast feet') are a group of bipedal saurischian dinosaurs.
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Sauropoda
Marsh, 1878

Families

See text

Sauropoda, the sauropods, are a suborder or infraorder of the saurischian ("lizard-hipped") dinosaurs. They were the largest animals ever to have lived on land.
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Harry Govier Seeley (18 February 1839 - 8 January 1909) was a British paleontologist who determined that dinosaurs fell into two great groups, the Saurischians and the Ornithischians, based on the nature of their pelvic bones and joints.
..... Click the link for more information.
18th century - 19th century - 20th century
1850s  1860s  1870s  - 1880s -  1890s  1900s  1910s
1884 1885 1886 - 1887 - 1888 1889 1890

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Subjects:     Archaeology - Architecture -
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pelvis (pl. pelvises or pelves) is the bony structure located at the base of the spine (properly known as the caudal end). The pelvis incorporates the socket portion of the hip joint for each leg (in bipeds) or hind leg (in quadrupeds).
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The Vertebral Column (singular: vertebra) are the individual irregular bones that make up the spinal column (aka ischis) — a flexuous and flexible column.
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Armour (or armor) in animals is external or superficial protection against attack by predators, formed as part of the body (rather than the behavioural use of protective external objects), usually through the hardening of body tissues, outgrowths or secretions.
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jaw is either of the two opposable structures forming, or near the entrance to, the mouth.

The term jaws is also broadly applied to the whole of the structures constituting the vault of the mouth and serving to open and close it.
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jaw is either of the two opposable structures forming, or near the entrance to, the mouth.

The term jaws is also broadly applied to the whole of the structures constituting the vault of the mouth and serving to open and close it.
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