Biology:Cladistic Classification of Class Sarcopterygii

From HandWiki
Short description: Taxonomy of lobe-finned fishes

Sarcopterygii or the lobe-finned fishes (coelacanths and lungfishes) were usually classified as either a class or a subclass of Osteichthyes based on the traditional Linnaean classification. Identification of the group is based on several characteristics, such as the presence of fleshy, lobed, paired fins, which are joined to the body by a single bone.[1]

Taxonomic and fossil history

The properties defining the sarcopterygians are in contrast to the other group of bony fish, the Actinopterygii, which have ray-fins made of bony rods, called lepidotrichia. These two bony fish groups were classified together as Osteichthyes at one time, the whole combined group was seen as the sister group to the tetrapods (mammals, birds, reptiles, and amphibians).

The extensive fossil record and numerous morphological and molecular studies have shown, however, that lungfish and some fossil lobe-finned fish are more closely related to tetrapods than they are to coelacanths; as a result tetrapods are nested within Sarcopterygii.[2][3] This abides to cladistics in that in order for a clade to be monophyletic, it must have an ancestral species and all descendants of that common ancestor based on shared characteristics. As such mammals, birds and reptiles, and amphibians are highly derived lobe-finned fish despite looking nothing like the standard sarcopterygian anatomically speaking.

Current taxonomy

The list below shows the taxonomy of the extant members of class Sarcopterygii at the ordinal level. While this does reflect the evolutionary relationships within the group, it also retains the rankings seen in the Linnaean classification as suggested by some scientists.[4] The evolutionary sequences are based from current phylogenetic work on the various subclades.[5][6][7][8][9][10]

Class Sarcopterygii Romer, 1955

See also

References

  1. ↑ Gaining Ground: The origin and evolution of tetrapods. Indiana University Press. 2012. ISBN 978-0-253-35675-8. 
  2. ↑ The variety of life. Oxford: Oxford University Press. 2000. ISBN 978-0-19-860426-6. 
  3. ↑ Vertebrate life. Pearson/Prentice Hall. 2005. ISBN 978-0-321-77336-4. 
  4. ↑ Fishes of the World.. John Wiley & Sons. April 2016. ISBN 978-1-118-34233-6. 
  5. ↑ "More than 1000 ultraconserved elements provide evidence that turtles are the sister group of archosaurs". Biology Letters 8 (5): 783–6. October 2012. doi:10.1098/rsbl.2012.0331. PMID 22593086. 
  6. ↑ "The draft genomes of soft-shell turtle and green sea turtle yield insights into the development and evolution of the turtle-specific body plan". Nature Genetics 45 (6): 701–706. June 2013. doi:10.1038/ng.2615. PMID 23624526. 
  7. ↑ "A phylogeny of birds based on over 1,500 loci collected by target enrichment and high-throughput sequencing". PLOS ONE 8 (1): e54848. 2013. doi:10.1371/journal.pone.0054848. PMID 23382987. Bibcode: 2013PLoSO...854848M. 
  8. ↑ "An Unbiased Molecular Approach Using 3'-UTRs Resolves the Avian Family-Level Tree of Life". Molecular Biology and Evolution 38 (1): 108–127. January 2021. doi:10.1093/molbev/msaa191. PMID 32781465. 
  9. ↑ "Mammals from 'down under': a multi-gene species-level phylogeny of marsupial mammals (Mammalia, Metatheria)". PeerJ 3: e805. 2015. doi:10.7717/peerj.805. PMID 25755933. 
  10. ↑ "The Interrelationships of Placental Mammals and the Limits of Phylogenetic Inference". Genome Biology and Evolution 8 (2): 330–44. January 2016. doi:10.1093/gbe/evv261. PMID 26733575. 




Retrieved from "https://handwiki.org/wiki/index.php?title=Biology:Cladistic_Classification_of_Class_Sarcopterygii&oldid=2804532"