Reptiliomorpha taxonomy

From Palaeos

Taxonomy

Subphylum: Vertebrata
Superclass: Tetrapoda
Class "Amphibia"
Superorder: REPTILIOMORPHA

o Tetrapoda crown group
`--o REPTILIOMORPHA 
   |--Embolomeri (=Anthracosauria)
   |?--Chroniosuchia
   `--o?--Gephyrostegidae
      `--+--Seymouriamorpha
         `--+--Westlothiana lizziae
            `--o--Diadectomorpha
               `--+--Casineria kiddi
                  `--o Amniota
                     |--Sauropsida
                     `--Synapsida

Reptiliomorpha is a name given either to reptile-like tetrapods, or to amniotes and those tetrapods related to them.

1 Changing Definitions
- 1.1 References
2 Current Taxonomy
3 Credits

[edit] Changing Definitions

The name Reptiliomorpha was coined by Professor Gunnar Säve-Söderbergh in 1934 to designate various types of late Paleozoic reptile-like labyrinthodont amphibians.

However Alfred Sherwood Romer used the name Anthracosauria instead, and this has been used until quite recently e.g. Carroll 1988.

In 1956 Friedrich von Huene included both amphibians and anapasid reptiles in the Reptiliomorpha. This included the following orders: 1. Anthracosauria, 2. Seymouriamorpha, 3. Microsauria, 4. Diadectomorpha, 5. Procolophonia, 6. Pareiasauria, 7. Captorhinidia, 8. Testudinata.

In 1997 Michel Laurin and Robert Reisz (1997) adapted the term in a cladistic sense. Michael Benton (2000, 2004) mades it the sister-clade to Batrachomorpha. However, when considered a linnean ranking, Reptiliomorpha is given the rank of superorder and only includes reptile-like amphibians [Systema Naturae 2000]. More recently Reptiliomorpha has been adopted as the term for the largest clade that includes - according to the technical definitions of the phylocode which only refers to species or genus level organisms - Homo sapiens but not Ascaphus truei ( a primitive frog) (International Phylogenetic Nomenclature Meeting 2003). Or, as Toby White puts it, more like dogs than frogs.

[edit] References

Benton, M. J. (2000), Vertebrate Palaeontology, 2nd Ed. Blackwell Science Ltd 3rd ed. 2004
Carroll, R. L., 1988: Vertebrate Paleontology and Evolution. W. H. Freeman and company, New York
Laurin, M. & Reisz, R. R., (1997): A new perspective on tetrapod phylogeny. 9-59 in Sumida, S. S. & Martin, K. L. M., 1997: Amniote origins: Completing the trasition to Land Academic Press, San Diego
Marjanovic, David, (2002) Re: thoughts on which nodes to name Dinosaur Mailing List
Second circular of the first International Phylogenetic Nomenclature Meeting 2003
Systema Naturae 2000 / Classification Superorder Reptiliomorpha
Von Huene, F., 1956, Palaontologie und Phylogenie der niederen Tetrapoden, G. Fischer, Jena.