Tetrapodomorpha
Tetrapodomorpha | |
---|---|
Life restoration of Megalichthys hibberti | |
Modern tetrapods | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Sarcopterygii |
Clade: | Rhipidistia |
Clade: | Tetrapodomorpha Ahlberg, 1991 |
Subgroups | |
See also below. |
Tetrapodomorpha (also known as Choanata
Among the characteristics defining tetrapodomorphs are modifications to the fins, notably a humerus with convex head articulating with the glenoid fossa (the socket of the shoulder joint). Another key trait is the internal nostril or choana. Most fish have two pairs of nostrils, one on either side of the head for incoming water (incurrent nostrils) and another pair for outgoing water (excurrent nostrils). In early tetrapodomorphs like Kenichthys, the excurrent nostrils had shifted towards the mouth's perimeter. In later tetrapodomorphs, including tetrapods, the excurrent nostril is positioned inside the mouth, where it is known as the choana.[4] The nearly-equivalent clade Choanata often refers to these later forms specifically.[2]
Tetrapodomorph fossils are known from the early Devonian onwards, and include Osteolepis, Panderichthys, Kenichthys and Tungsenia.[1]
Classification
Taxonomy
After Benton, 2004;[6] and Swartz, 2012.[7]
- Subclass Sarcopterygii
- Infraclass Tetrapodomorpha
- Order †Rhizodontida
- Family †Sauripteridae
- Family †Rhizodontidae
- Family †
- Superorder †Osteolepidida(or Osteolepiformes)
- Family †Canowindridae
- Family †Thysanolepidae
- Family †Tristichopteridae
- Order †Osteolepiformes (or Megalichthyiformes)
- Family †Osteolepidae
- Family †Megalichthyidae
- Family †
- Clade Eotetrapodiformes
- Clade Elpistostegalia (or Panderichthyida)
- Clade Stegocephalia
- Family †Elpistostegidae
- Family †Whatcheeriidae
- Family †Colosteidae
- Superfamily †Baphetoidea
- Superclass Tetrapoda
- Family †
- Clade
Other clades include the Eotetrapodiformes (Tinirau, Platycephalichthys, the Tristichopteridae and Elpistostegalia).[7] Older taxa which include late stem tetrapods and early tetrapods are the Labyrinthodontia and Ichthyostegalia.
Relationships
The cladogram is based on a phylogenetic analysis of 46 taxa using 204 characters by B. Swartz in 2012.[7]
Tetrapodomorpha | |
The following cladogram follows the results found by Clement et al. (2021).[8]
Dipnomorpha
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Tetrapodomorpha |
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References
- ^ PMID 23093197.
- ^ a b Merck, John. "And Now For Something Completely Different: Sarcopterygii".
- ISBN 978-0-203-46803-6. Retrieved 5 August 2015.
- ISBN 978-0-253-35675-8. Retrieved 8 June 2015.
- PMID 20739322.
- ^ "VERTAPPENDIX". palaeo.gly.bris.ac.uk. Archived from the original on 2005-03-21.
- ^ PMID 22448265.
- ISSN 2167-8359.
- Mikko Haaramo. "Tetrapodomorpha – Terrestrial vertebrate-like sarcopterygians". Archived from the original on 12 May 2006. Retrieved 6 April 2006.
- P. E. Ahlberg & Z. Johanson (1998). "Osteolepiforms and the ancestry of tetrapods". S2CID 4430783.
- Michel Laurin, Marc Girondot & Armand de Ricqlès (2000). "Early tetrapod evolution" (PDF). TREE. 15 (3).