Porolepiformes

Porolepiformes; Temporal range: Devonian and Carboniferous
	Various genera
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Sarcopterygii
Clade:	Rhipidistia
Clade:	Dipnomorpha
Class:	Porolepimorpha
Order:	†Porolepiformes; Jarvik 1942
Genera
	†Porolepidae †Heimenia ØRvik 1969; †Porolepis; ; †Holoptychiidae Owen 1860 ?†Duffichthys Ahlberg 1992; ?†Ventalepis Schultze 1980; †Pseudosauripterus ; †Glyptolepis; †Holoptychius; †Laccognathus; ;

Porolepiformes is an order of prehistoric lobe-finned fish which lived during the Devonian period (about 416 to 359 million years ago). They are thought to represent the sister group to lungfish (class Dipnoi).^[1] The group contains two families: Holoptychiidae and Porolepididae.

Porolepiformes was established by the Swedish paleontologist Erik Jarvik, and were thought to have given rise to the salamanders and caecilians independently of the other tetrapods.^[2] He based this conclusion on the shapes of the snouts of the aforementioned groups. This view is no longer in favour in Paleontology.^[3]

Jarvik also claimed the existence of choanae in porolepiformes which linked them to tetrapods, but this has remained controversial.^[4] Recent phylogenetic reconstruction places porolepiformes close to lungfishes.^[5]

More recent evidence has shown that at least one genus Laccognathus was most likely amphibious.^[6]

^ Nelson, Joseph S. (16 March 2016). Fishes of the World. ISBN 978-1-119-22081-7. OCLC 951128215.
^ Jarvik, Erik. 1980. Basic structure and evolution of vertebrates. Vol. 1–2. Academic Press (London).
^ Schultze, Hans-Peter & Trueb, Linda (1991). Origins of the higher groups of tetrapods: controversy and consensus. Cornell University Press. p. 37. ISBN 978-0-8014-2497-7.
^ Clement, G., 2001. Evidence for lack of choanae in the Porolepiformes. Journal of Vertebrate Paleontology, 21: 795–802.
^ Janvier , P., Early vertebrates. Oxford science publications. 1996, Oxford, New York: Clarendon Press; Oxford University Press.
^ Vorobyeva, E.I. (2006). "A new species of Laccognathus (Porolepiform Crossopterygii) from the Devonian of Latvia". Paleontol. J. 40 (3). Physorg.com: 312–322. doi:10.1134/S0031030106030129. S2CID 129696592.

[1] Nelson, Joseph S. (16 March 2016). Fishes of the World. ISBN 978-1-119-22081-7. OCLC 951128215.

[2] Jarvik, Erik. 1980. Basic structure and evolution of vertebrates. Vol. 1–2. Academic Press (London).

[schultze-3] Schultze, Hans-Peter & Trueb, Linda (1991). Origins of the higher groups of tetrapods: controversy and consensus. Cornell University Press. p. 37. ISBN 978-0-8014-2497-7.

[4] Clement, G., 2001. Evidence for lack of choanae in the Porolepiformes. Journal of Vertebrate Paleontology, 21: 795–802.

[5] Janvier , P., Early vertebrates. Oxford science publications. 1996, Oxford, New York: Clarendon Press; Oxford University Press.

[vorobyeva-6] Vorobyeva, E.I. (2006). "A new species of Laccognathus (Porolepiform Crossopterygii) from the Devonian of Latvia". Paleontol. J. 40 (3). Physorg.com: 312–322. doi:10.1134/S0031030106030129. S2CID 129696592.

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