What is Diapsid?

Information about Diapsid

Diapsids
Fossil range: Carboniferous-Recent
Enlarge picture
the diapsid skull

the diapsid skull
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Sauropsida
(unranked)Eureptilia
Subclass:Diapsida
Osborn, 1903
Groups


See text


Diapsids ("two arches") are a group of tetrapod animals that developed two holes (temporal fenestra) in each side of their skulls, about 300 million years ago during the late Carboniferous period. Living diapsids are extremely diverse, and include all birds, crocodiles, lizards, snakes, tuatara, and possibly even turtles. While some lost either one hole (lizards), or both holes (snakes), or even have a much more restructured skull (modern birds), they are still classified as diapsids based on their ancestry. There are 14,600 species of diapsid existing in environments around the world today, including most flying and venomous vertebrates.

The ancestral openings are above and below the eye. This arrangement allows for the attachment of larger, stronger, jaw muscles and enables the jaw to open more widely. A more obscure ancestral characteristic is a relatively long lower arm bone (radius), compared to the upper arm bone (humerus). Extinct groups include the dinosaurs, pterosaurs, plesiosaurs, mosasaurs, and many more obscure lineages. The classification of most of the early groups is fluid and subject to change.

Taxonomy

Classification

Phylogeny

DiapsidaAraeoscelida?Sphodrosaurus?Palacrodon?Omphalosaurus `--+--Avicephala `--NeodiapsidaApsisaurus `--Eosuchia?Younginiformes `--+-?Claudiosaurus?Ichthyopterygia `--Sauria?ThalattosauriformesLepidosauromorpha `--Archosauromorpha

See also

External links






Caption: Skull of false gharial (Tomistoma schlegeli)
The Carboniferous is a major division of the geologic timescale that extends from the end of the Devonian period, about 359.2 ± 2.5 Ma (million years ago), to the beginning of the Permian period, about 299.0 ± 0.8 Ma (ICS 2004).
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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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Eureptilia
Olson, 1947

Clades
  • Captorhinidae
  • Romeriida


Eureptilia ("true reptiles") is one of the two major clades of the Sauropsida, the other being Anapsida (or Parareptilia).
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Henry Fairfield Osborn (August 8, 1857–November 6, 1935) was an American geologist, paleontologist, and eugenicist.

Biography

Osborn was born in Fairfield, Connecticut, and studied at Princeton University.
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19th century - 20th century - 21st century
1870s  1880s  1890s  - 1900s -  1910s  1920s  1930s
1900 1901 1902 - 1903 - 1904 1905 1906

Year 1903 (MCMIII
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Tetrapoda
Broili, 1913

Classes
  • Amphibia
  • Aves
  • Mammalia
  • Sauropsida (Reptilia)
  • Synapsida
Tetrapods (Greek tetrapoda, Latin quadruped
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skull is a bony structure found in many animals which serves as the general framework for the head. The skull supports the structures of the face and protects the head against injury.

The skull can be subdivided into two parts: the cranium and the mandible.
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Annum is a Latin noun meaning year. It is the accusative singular of the second declension masculine noun annus (nominative), anni (genitive) [1] .

As a unit of time, it is defined as exactly 365.
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The Carboniferous is a major division of the geologic timescale that extends from the end of the Devonian period, about 359.2 ± 2.5 Ma (million years ago), to the beginning of the Permian period, about 299.0 ± 0.8 Ma (ICS 2004).
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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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Crocodylidae
Cuvier, 1807

Genera
  • Mecistops
  • Crocodylus
  • Osteolaemus
See full taxonomy.
A crocodile is any species belonging to the family Crocodylidae
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Lacertilia*
Günther, 1867

Families

Many, see text.

Lizards are reptiles of the order Squamata, normally possessing four legs, external ear openings and movable eyelids.
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Serpentes
Linnaeus, 1758

Infraorders and Families
  • Alethinophidia - Nopcsa, 1923
  • Acrochordidae- Bonaparte, 1831

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Sphenodon
Gray, 1831

black: range (North Island, New Zealand)


Species

Sphenodon punctatus (Gray, 1842)
Sphenodon guntheri (Buller, 1877)
Sphenodon diversum
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Testudines
Linnaeus, 1758

Diversity
ca. 300 species in 14 extant families.

blue: sea turtles, black: land turtles


Suborders

Cryptodira
Pleurodira
See text for families.
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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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species is one of the basic units of biological classification. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring.
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Flight is the process by which an object achieves sustained movement either through the air by aerodynamically generating lift or aerostatically using buoyancy, or movement beyond earth's atmosphere, in the case of spaceflight.
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Venom (literally, poison of animal origin) is any of a variety of toxins used by certain types of animals, for the purpose of defense and hunting. Generally, venom is injected while other toxins are absorbed by ingestion or through the skin.
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Vertebrata
Cuvier, 1812

Classes and Clades

See below
Vertebrates are members of the subphylum Vertebrata (within the phylum Chordata), specifically, those chordates with backbones or spinal columns.
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The radius is the bone of the forearm that extends from the outside of the limb to the phlangx (lateral) of the elbow to the thumb side of the wrist. The radius is situated on the lateral side of the ulna, which exceeds it in length and size.
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The humerus is a long bone in the arm or fore-legs (animals) that runs from the shoulder to the elbow. On a skeleton, it fits between the scapula and the ulna. It consists of the following three sections:
  • Upper extremity of humerus
  • Body of humerus

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Dinosauria *
Owen, 1842

Orders & Suborders
  • Ornithischia
  • Cerapoda
  • Thyreophora
  • Saurischia

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Pterosauria
Kaup, 1834

Suborders

Pterodactyloidea
Rhamphorhynchoidea *

Pterosaurs (/ˈtɛ.
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Plesiosauroidea
Gray, 1825

Families

Cimoliasauridae
Cryptoclididae
Elasmosauridae
Plesiosauridae
Polycotylidae

Plesiosaurs (IPA /ˈplisɪəˌsɔɹ/
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Mosasauridae
Gervais, 1853

Subfamilies

Halisaurinae
Mosasaurinae
Plioplatecarpinae
Tylosaurinae

Mosasaurs (from Latin Mosa meaning the 'Meuse river' in the Netherlands, and Greek sauros
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Araeoscelidia or Araeoscelida is a clade of extinct diapsid reptiles superficially resembling lizards. It contains the genera Araeoscelis, Petrolacosaurus, the possibly aquatic Spinoaequalis, and less well-known genera such as Kadaliosaurus
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