Systematics of the reptiles

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Scope of the reptiles of the classical system, shown in a cladogram : The birds (Aves) and "higher" synapsids (i.e. the mammals) are not included despite their common descent.

The reptiles (Reptilia) are in the classical system a class of vertebrates (Vertebrata).

From a cladistic point of view, the reptiles of the traditional system are a paraphyletic group or a form taxon , because the birds (Aves) are not counted among them due to numerous deviating external characteristics, although reptiles and birds form a community of descent ( clade ). The taxon Sauropsida , which was introduced by Huxley in 1864 to unite birds and reptiles , is therefore often preferred today . However, the group name "Reptilia" is so well established that it is mainly used by paleontologists , including birds. However, today's reptiles not only share a common, albeit older, ancestor with birds, but also with today's mammals (Mammalia). The clade from sauropsids and mammals is called amniotes .

The reptiles of the traditional system can also be defined as “exclusion taxons”: reptiles are all amniotes that are neither mammals nor birds. While in this way a clear demarcation between on the one hand reptiles in the traditional sense and on the other hand mammals and birds is possible, these boundaries become blurred as soon as one goes back about 100 to 300 million years in the history of the earth, because the ancestors of today's mammals and birds possessed this Numerous typical reptile features at the time. For this reason, it is controversial among biologists and paleontologists where exactly the dividing line between the actual birds (Aves) and the non-avian sauropsids or the actual mammals (Mammalia) and the mammal ancestors (non-mammal) that are still reptilian to a certain degree is disputed Synapsids ).

The recent reptiles (in the traditional sense) are therefore amniotes, which have numerous typical characteristics of the early representatives of this group, u. a. the cold-bloodedness and the associated lack of hair or plumage have persisted to this day. These include the turtles , the scalloped reptiles with snakes and lizards and the crocodiles . In contrast, many typical reptilian traits in the lines of development that lead to mammals and birds have either disappeared or have been greatly modified.

The following system lists the today living as well as the best known extinct (†) taxa down to the family level (ending: ... idae ) (exception: dinosaurs).

Reptilia

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Individual evidence

  1. ↑ Robert Alexander Pyron, Frank T. Burbrink, John J. Wiens: A phylogeny and revised classification of Squamata, including 4161 species of lizards and snakes. BMC Evolutionary Biology, Vol. 13, Item No. 93, 2013, doi: 10.1186 / 1471-2148-13-93