Rhipidistia, also known as Dipnotetrapodomorpha,[1] is a clade of lobe-finned fishes which includes the tetrapods and lungfishes. Rhipidistia formerly referred to a subgroup of Sarcopterygii consisting of the Porolepiformes and Osteolepiformes, a definition that is now obsolete.[2] However, as cladistic understanding of the vertebrates has improved over the last few decades, a monophyletic Rhipidistia is now understood to include the whole of Tetrapoda and the lungfishes.
Rhipidistia includes Porolepiformes and Dipnoi. Extensive fossilization of lungfishes has contributed to many evolutionary studies of this group. Evolution of autostylic jaw suspension, in which the palatoquadrate bone fuses to the cranium, and the lymph pumping "lymph heart" (later lost in mammals and flying birds), are unique to this group. Another feature shared by lungfish and tetrapods is the divided atrium.[3]
The precise time at which the choana of tetrapods evolved is debated, with some considering early rhipidistians as the first choanates. The feature is also present in modern lungfish but is probably a case of convergent evolution. The basal stem-lungfish Diabolepis did not possess it. Instead, it had four nostrils (two anterior and two posterior) like most fish. However, its posterior nares are very close to the lip, meaning a ventral 'displacement' of the posterior nostril can be considered a synapomorphy of the lungfish-tetrapod clade. The complete choana then seems to have developed independently in the two surviving clades.[4]
Rhipidistia is from Ancient Greek ῥιπίδιον (rhipídion, "small bellows")
Dipnotetrapodomorpha is from the Greek δίπνοος (dipnoos) with two breathing structures; and from δι- twice and πνοή breathing, breath; and from ancient Greek τετρα- (tetra-), combining form of the numeral τέτταρες (tettares), and ancient Greek -ποδ- (-pod-)the combining form of πούς (pous, foot); and ancient Greek -μορϕος (-morphos), combining form of μορϕή (morph) physical shape.
Relationshipsedit
The cladogram presented below is based on studies compiled by Philippe Janvier and others for the Tree of Life Web Project,[5] and Swartz 2012.[6]
^"Encyclopædia Britannica". Retrieved 3 April 2014.
^Pough, F. Harvey (2018). Vertebrate Life. Christine M. Janis, Sergi López-Torres (10th ed.). New York: Oxford University Press. p. 123. ISBN978-1-60535-607-5. OCLC 1022979490.
^Zhu, Min; Ahlberg, Per E. (2004). "The origin of the internal nostril of tetrapods". Nature. 432 (7013): 94–97. Bibcode:2004Natur.432...94Z. doi:10.1038/nature02843. ISSN 0028-0836. PMID 15525987. S2CID 4422813.
^Swartz, B. (2012). "A marine stem-tetrapod from the Devonian of Western North America". PLOS ONE. 7 (3): e33683. Bibcode:2012PLoSO...733683S. doi:10.1371/journal.pone.0033683. PMC3308997. PMID 22448265.
rhipidistia, also, known, dipnotetrapodomorpha, clade, lobe, finned, fishes, which, includes, tetrapods, lungfishes, formerly, referred, subgroup, sarcopterygii, consisting, porolepiformes, osteolepiformes, definition, that, obsolete, however, cladistic, under. Rhipidistia also known as Dipnotetrapodomorpha 1 is a clade of lobe finned fishes which includes the tetrapods and lungfishes Rhipidistia formerly referred to a subgroup of Sarcopterygii consisting of the Porolepiformes and Osteolepiformes a definition that is now obsolete 2 However as cladistic understanding of the vertebrates has improved over the last few decades a monophyletic Rhipidistia is now understood to include the whole of Tetrapoda and the lungfishes RhipidistiansTemporal range Early Devonian Present 416 0 Ma PreꞒ Ꞓ O S D C P T J K Pg NScientific classificationDomain EukaryotaKingdom AnimaliaPhylum ChordataClade SarcopterygiiClade RhipidistiaSubgroupsDipnomorpha Porolepiformes Dipnoi lungfish TetrapodomorphaRhipidistia includes Porolepiformes and Dipnoi Extensive fossilization of lungfishes has contributed to many evolutionary studies of this group Evolution of autostylic jaw suspension in which the palatoquadrate bone fuses to the cranium and the lymph pumping lymph heart later lost in mammals and flying birds are unique to this group Another feature shared by lungfish and tetrapods is the divided atrium 3 The precise time at which the choana of tetrapods evolved is debated with some considering early rhipidistians as the first choanates The feature is also present in modern lungfish but is probably a case of convergent evolution The basal stem lungfish Diabolepis did not possess it Instead it had four nostrils two anterior and two posterior like most fish However its posterior nares are very close to the lip meaning a ventral displacement of the posterior nostril can be considered a synapomorphy of the lungfish tetrapod clade The complete choana then seems to have developed independently in the two surviving clades 4 Contents 1 Etymology 2 Relationships 3 References 4 External linksEtymology editRhipidistia is from Ancient Greek ῥipidion rhipidion small bellows Dipnotetrapodomorpha is from the Greek dipnoos dipnoos with two breathing structures and from di twice and pnoh breathing breath and from ancient Greek tetra tetra combining form of the numeral tettares tettares and ancient Greek pod pod the combining form of poys pous foot and ancient Greek morϕos morphos combining form of morϕh morph physical shape Relationships editThe cladogram presented below is based on studies compiled by Philippe Janvier and others for the Tree of Life Web Project 5 and Swartz 2012 6 Sarcopterygii OnychodontidaeActinistia coelacanths Rhipidistia StyloichthysDipnomorpha PorolepiformesDipnoi lungfishes Tetrapodomorpha Tungsenia Kenichthys Rhizodontiformes Thysanolepidae Canowindridae OsteolepiformesEotetrapodiformes Tristichopteridae Tinirau PlatycephalichthysElpistostegalia Panderichthys ElpistostegidaeStegocephalia Elginerpetontidae Metaxygnathus VentastegaTetrapodaReferences edit Joseph S Nelson 19 May 2006 Fishes of the World John Wiley amp Sons p 461 ISBN 978 0 471 75644 6 Retrieved 9 May 2015 Encyclopaedia Britannica Retrieved 3 April 2014 Pough F Harvey 2018 Vertebrate Life Christine M Janis Sergi Lopez Torres 10th ed New York Oxford University Press p 123 ISBN 978 1 60535 607 5 OCLC 1022979490 Zhu Min Ahlberg Per E 2004 The origin of the internal nostril of tetrapods Nature 432 7013 94 97 Bibcode 2004Natur 432 94Z doi 10 1038 nature02843 ISSN 0028 0836 PMID 15525987 S2CID 4422813 Janvier Philippe 1997 Vertebrata Animals with backbones Version 01 January 1997 under construction http tolweb org Vertebrata 14829 1997 01 01 in The Tree of Life Web Project http tolweb org Swartz B 2012 A marine stem tetrapod from the Devonian of Western North America PLOS ONE 7 3 e33683 Bibcode 2012PLoSO 733683S doi 10 1371 journal pone 0033683 PMC 3308997 PMID 22448265 External links editpalaeos com page Taxonomicon page nbsp This article about a prehistoric lobe finned fish is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Rhipidistia amp oldid 1179150724, wikipedia, wiki, book, books, library,
