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Information about Saurischia

Saurischian dinosaurs
Fossil range: Triassic - Cretaceous (non-avian)
Enlarge picture
Saurischian pelvic structure (left side)

Saurischian pelvic structure (left side)
Conservation status
Extinct (fossil)
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Sauropsida
Superorder:Dinosauria
Order:Saurischia
Seeley, 1887
Suborders
Enlarge picture
Tyrannosaurus rex saurischian pelvis and hind limbs (left side), taken at the Oxford University Museum of Natural History.


Saurischia (from the Greek sauros (σαυρος) meaning 'lizard' and ischion (ισχιον) meaning 'hip joint') is one of the two orders/branches of dinosaurs. In 1888, Harry Seeley classified dinosaurs into two great orders, based on their hip structure. Saurischians ('lizard-hipped') are distinguished from the ornithischians ('bird-hipped') by retaining the ancestral configuration of bones in the hip. All carnivorous dinosaurs (the theropods) are saurischians, as are one of the two great lineages of herbivorous dinosaurs, the sauropodomorphs. At the end of the Cretaceous Period, all non-avian saurischians became extinct. This is referred to as the Cretaceous-Tertiary extinction event.

The saurischian lineage diverged from the ornithischians in the late Triassic Period, and retained a three-pronged pelvic structure, with the pubis pointed forward, until some advanced forms in the group Maniraptora reversed this, in parallel with the ornithischian condition. The ornithischians evolved a new hip structure, with the pubis rotating caudally, to become parallel with the ischium, often also with a forward-pointing process, giving a four-pronged structure. This hip structure is similar to that of birds, and so ornithischians are termed 'bird-hipped' dinosaurs, while the saurischians are 'lizard-hipped'. The true bird-hip possessed by modern birds evolved independently in the lizard-hipped theropods in the Jurassic Period, an example of convergent evolution.

While Seeley's classification has stood the test of time, there is a minority theory, first popularized by Robert Bakker in The Dinosaur Heresies that separates the theropods into their own group and places the two great groups of herbivorous dinosaurs (the sauropodomorphs and ornithischians) together in a separate group he named the Phytodinosauria ('plant dinosaurs') (Bakker), or Ornithischiformes (Cooper).

Taxonomy

Classification

Additionally, the genera Teyuwasu and Agnosphitys may represent early saurischians, or more primitive non-dinosaurs.

Phylogeny

The following cladogram is adapted from Weishampel et al., 2004.[1]

 Saurischia  label4= Theropoda 

 Herrerasauria



 Carnosauria 


  Coelurosauria 





References

1. ^ Weishampel, David B.; Dodson, Peter; Osmólska, Halszka (eds.) (2004). The Dinosauria, Second Edition. University of California Press., 861 pp.
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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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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Theropoda
Marsh, 1881

Infraorders
  • Carnosauria
  • Ceratosauria
  • Deinonychosauria
  • Ornithomimosauria
  • Oviraptorosauria


Theropods ('beast feet') are a group of bipedal saurischian dinosaurs.
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Sauropodomorpha
von Huene, 1932

Infraorders

Prosauropoda
Sauropoda

The Sauropodomorpha were a group of long-necked, herbivorous dinosaurs that eventually dropped down on all fours and became the largest animals that ever walked the earth.
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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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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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Dinosauria *
Owen, 1842

Orders & Suborders
  • Ornithischia
  • Cerapoda
  • Thyreophora
  • Saurischia

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8th century - 9th century - 10th century
850s  860s  870s  - 880s -  890s  900s  910s
885 886 887 - 888 - 889 890 891

:
Subjects:     Archaeology - Architecture -
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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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Ornithischia
Seeley, 1888

Suborders
  • Cerapoda
  • Thyreophora


Ornithischia or Predentata is an order of beaked, herbivorous dinosaurs.
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carnivore (IPA: /ˈkɑrnɪvɔər/), meaning 'meat eater' (Latin carne meaning 'flesh' and vorare
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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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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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Sauropodomorpha
von Huene, 1932

Infraorders

Prosauropoda
Sauropoda

The Sauropodomorpha were a group of long-necked, herbivorous dinosaurs that eventually dropped down on all fours and became the largest animals that ever walked the earth.
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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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A geologic period is a subdivision of geologic time that divides an era into smaller timeframes. The equivalent term used to demarcate rock layers and the fossil record is the system; thus the rocks of the Devonian System were laid down during the Devonian Period.
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Avian may refer to:
  • Bird
  • Avian (band), an American metal band
  • Avians, a fantasy race in several fantasy settings

See also

  • Avian influenza, also known as Avian bird flu

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extinction is the cessation of existence of a species or group of taxa, reducing biodiversity. The moment of extinction is generally considered to be the death of the last individual of that species (although the capacity to breed and recover may have been lost before this point).
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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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Maniraptora
Gauthier, 1986

Subclades

See text.
Maniraptora ("hand snatchers") is a clade of coelurosaurian dinosaurs used in phylogenetic taxonomy which covers the birds and the dinosaurs that were most closely related to them.
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Pubis may refer to the following:
  • Pubis (bone)
  • Mons pubis, a padding of fat that protects the pubis bone

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The ischium forms the lower and back part of the hip bone. It is situated below the ilium. The word comes from the Greek ischion, meaning "hip." (Taber's, 1985)

It is divisible into three portions:
  • Body of ischium
  • Superior ramus of the ischium

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