Reptiles

reptiles
Mauri land turtle (test Udo graeca)
systematics
Master's group: New mouths (Deuterostomia)
trunk: Choir-date (choir DATA)
Unterstamm: Vertebrate animals (Vertebrata)
over class: Kiefermäuler (Gnathostomata)
row: Land vertebrate animals (Tetrapoda)
class: Reptiles
scientific name
Reptilia
Laurenti, 1768
orders

the reptiles (Reptilia) or reptiles (lat.: reptilis - creeping) form a class of the vertebrate animals. As phylogenetisches Taxon or as closed group of descending they would have to contain also the birds. In the classical composition shown here the reptiles are accordingly no natural group, but a paraphyletisches Taxon, because they contain not all descendants of their last common moving forward.

There is change-warm animals, which possess tail, one skin with horn sheds and usually four legs, which were regressed however with the queues. Reptiles breathe by lungs. They put eggs to bear or living boy (egg-living-bearing, ovovivipar) and develop directly, i.e. without larvae - to Zwischenform.

descending history

evolutionary the reptiles including the birds descend from amphibious land vertebrate animals. Substantial distinguisher is that Amphibians Amnion, which surrounds the developing embryo do not possess. The remaining land vertebrate animals are called thereafter also Amnioten (Amniota). The Amnioten is not dependent contrary to the Amphibians for reproduction on waters, and also generally better adapted to dry habitats.

The Amniota split into two branches, those after the characteristic number and situation of lateral openings up in the head, the Schläfen - or speed ral windows, as Synapsida (an opening) and Diapsida (two openings) to be designated; the Ur-Amniota did not have openings (Anapsida). From the Diapsida the reptiles with as well-known groups come as the dinosaurs (Dinosauria) or the become extinct Flugsauriern (Pterosauria). As this very day living (rezente) representatives of the dinosaurs the birds are considered in newer opinion.

So far inexplicably is the systematic position of the turtles (Testudinata): Their head does not exhibit lateral openings, therefore this group is assigned mostly the Anapsiden; some paleontologists assume however that the turtles are descendants of Diapsiden, which reduced their sleep openings in the following. Also due to the situation of the Halsarterien and the training of the Aorta they are arranged today in the relationship of the reptiles as group of sisters of the Archosauria. The fossil situation permits at present no final clarifying.

The first reptiles step in the early Permian before approximately 300 millions Years up. A first fragmentation took place very early in improper reptiles (Parareptilia) and actual reptiles (Eureptilia). Representatives of the Parareptilia are the Procolophonida become extinct in the Trias, which are often regarded as of the turtles relatives close, and which already in the Permian Pareiasauria become extinct.

The Eureptilia split up into a multiplicity of branches. The branch of the Archosauria covers the crocodiles, the Flugsaurier and the dinosaurs including the birds. The parallel branch of the Leptosauria contains the close related Echsen, queues and double creeping, as well as the somewhat more removed Brückenechsen. Finally the Sauropterygia or Flossenechsen is to be called, a group of become extinct sea reptiles from the Mesozoikum.

systematics

version 1 (classical version): Turtles as Anapsida

Phylogenetisches System der Sauropsida (Version 1)
Phylogeneti system of the Sauropsida (version 1)

in this version represent the reptiles a perfectly artificial group (Polyphylum), since they exclude both the Synapsida (with the mammals) and the birds:

version 2: Turtles as group of sisters of the Archosauria, “reptiles” and birds as Sauropsida

in this case form the reptiles still no complete natural group, since they exclude the birds. The alternative Sauropsida, which covers the birds as part of the Dinosauria also, are however a genuine Taxon:

see also: Systematics of the reptiles

the scientific occupation with reptiles fall into the area of the Herpetologie.

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