# Redfieldiiformes

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Extinct order of ray-finned fishes

Redfieldiiformes Temporal range: Induan–Sinemurian PreꞒ Ꞓ O S D C P T J K Pg N Dictyopyge macrurus from the Late Triassic of Virginia Scientific classification Kingdom: Animalia Phylum: Chordata Class: Actinopterygii Subclass: Neopterygii (?) Order: †Redfieldiiformes Berg, 1940 Type genus †Redfieldius Hay, 1899 Families Brookvaliidae Redfieldiidae

**Redfieldiiformes** is an [extinct](/source/Extinct) [order](/source/Order_(biology)) of [ray-finned fish](/source/Ray-finned_fish) (actinopterygians) which lived from the [Early Triassic](/source/Early_Triassic) to [Early Jurassic](/source/Early_Jurassic). Redfieldiiforms were fairly typical Triassic fish in overall anatomy. They had a [fusiform](/source/Fusiform) (streamlined, [tuna](/source/Tuna)-like) body shape with thick, [ganoine](/source/Ganoine)-covered scales. The [dorsal](/source/Dorsal_fin) and [anal](/source/Anal_fin) fins were large, positioned opposite from each other, and shifted back, close to the tail. The [caudal fin](/source/Caudal_fin) was hemiheterocercal, with the vertebral column and body scales extending into an upper lobe equal in size and shape to the lower lobe. They also had several characteristic skeletal traits, such as a hatchet-shaped [preopercle](/source/Preopercle), a series of fulcra (thin spiny scales) fringing the fins, a reduced number of [branchiostegal rays](/source/Branchiostegal_rays) (typically just one), and a snout ornamented with tubercles.[1][2][3]

The [maxilla](/source/Maxilla) has small teeth and is strongly connected to the preopercle; this would have allowed a deep gape to assist in [ram feeding](/source/Ram_feeding).[1] The function of the snout tubercles is uncertain; some authors have suggested that they attached to a fleshy upper lip,[2] while others argue that they could have held sensory organs akin to the tubercles of siluriforms ([catfish](/source/Catfish)).[3]

Redfieldiiforms were fairly primitive 'subholostean' fish (more primitive than [holosteans](/source/Holostei) such as [gars](/source/Gar) or the [bowfin](/source/Bowfin)), with uncertain relations to [neopterygians](/source/Neopterygii).[1] Some studies draw comparisons to '[perleidiforms](/source/Perleidiformes)' or [ptycholepids](/source/Ptycholepiformes), while others consider redfieldiiforms to be early neopterygians related to [pholidopleuriforms](/source/Pholidopleuriformes).[4] Redfieldiiforms were exclusively freshwater fish which became prominent in southern [Gondwana](/source/Gondwana) ([Argentina](/source/Argentina), [Australia](/source/Australia), southern [Africa](/source/Africa)) during the Middle Triassic.[3] By the [Late Triassic](/source/Late_Triassic) they had become a major component of freshwater ecosystems in western [Laurasia](/source/Laurasia) ([North America](/source/North_America) and [Morocco](/source/Morocco)). However, they were much rarer further east ([South Korea](/source/South_Korea),[3] possibly [Switzerland](/source/Switzerland)[5]). The last member of the order, *[Redfieldius](/source/Redfieldius)*, lived in the Early Jurassic of eastern North America.[1][3]

## Taxonomy

The following families and genera are known:

- Order **Redfieldiiformes** - Genus *[Calaichthys](https://en.wikipedia.org/w/index.php?title=Calaichthys&action=edit&redlink=1)*[1] - Genus *[Denwoodichthys](https://en.wikipedia.org/w/index.php?title=Denwoodichthys&action=edit&redlink=1)?* - Genus *[Helichthys](/source/Helichthys)* - Genus *[Hiascoactinus](https://en.wikipedia.org/w/index.php?title=Hiascoactinus&action=edit&redlink=1)*[3] - *Genus [Pacorichthys](/source/Pacorichthys)?*[5] - Genus *[Sakamenichthys](/source/Sakamenichthys)?* - Genus *[Sinkiangichthys](https://en.wikipedia.org/w/index.php?title=Sinkiangichthys&action=edit&redlink=1) ([nomen dubium](/source/Nomen_dubium))?* - Family [Brookvaliidae](https://en.wikipedia.org/w/index.php?title=Brookvaliidae&action=edit&redlink=1) - Genus *[Atopocephala](/source/Atopocephala)* - Genus *[Brookvalia](/source/Brookvalia)* - Genus *[Ischnolepis](https://en.wikipedia.org/w/index.php?title=Ischnolepis_(fish)&action=edit&redlink=1)* - Genus *[Phlyctaenichthys](https://en.wikipedia.org/w/index.php?title=Phlyctaenichthys&action=edit&redlink=1)* - Genus *[Schizurichthys](https://en.wikipedia.org/w/index.php?title=Schizurichthys&action=edit&redlink=1)* (formerly placed in the family Schizurichthyidae) - Family [Redfieldiidae](/source/Redfieldiidae) - Genus *[Cionichthys](/source/Cionichthys)* - Genus *[Endemichthys](https://en.wikipedia.org/w/index.php?title=Endemichthys&action=edit&redlink=1)?* - Genus *[Daedalichthys](/source/Daedalichthys)* - Genus *[Dictyopyge](/source/Dictyopyge)* - Genus *[Geitonichthys](https://en.wikipedia.org/w/index.php?title=Geitonichthys&action=edit&redlink=1)* - Genus *[Lasalichthys](https://en.wikipedia.org/w/index.php?title=Lasalichthys&action=edit&redlink=1)* (=*Synorichthys*)[6] - Genus *[Mauritanichthys](/source/Mauritanichthys)* - Genus *[Molybdichthys](https://en.wikipedia.org/w/index.php?title=Molybdichthys&action=edit&redlink=1)* - Genus *[Redfieldius](/source/Redfieldius)*

## References

1. ^ [***a***](#cite_ref-:1_1-0) [***b***](#cite_ref-:1_1-1) [***c***](#cite_ref-:1_1-2) [***d***](#cite_ref-:1_1-3) [***e***](#cite_ref-:1_1-4) Gouiric-Cavalli, Soledad; Zavattieri, Ana M.; Gutierrez, Pedro R.; Cariglino, Bárbara; Balarino, Lucía (2017). ["Increasing the fish diversity of the Triassic faunas of Gondwana: a new redfieldiiform (Actinopterygii) from the Middle Triassic of Argentina and its palaeobiogeographical implications"](https://onlinelibrary.wiley.com/doi/abs/10.1002/spp2.1089). *Papers in Palaeontology*. **3** (4): 559–581. [doi](/source/Doi_(identifier)):[10.1002/spp2.1089](https://doi.org/10.1002%2Fspp2.1089). [hdl](/source/Hdl_(identifier)):[11336/57303](https://hdl.handle.net/11336%2F57303). [ISSN](/source/ISSN_(identifier)) [2056-2802](https://search.worldcat.org/issn/2056-2802). [S2CID](/source/S2CID_(identifier)) [134580710](https://api.semanticscholar.org/CorpusID:134580710).

1. ^ [***a***](#cite_ref-:2_2-0) [***b***](#cite_ref-:2_2-1) Gibson, Sarah Z. (2018-09-03). ["A new species of *Lasalichthys* (Actinopterygii, Redfieldiiformes) from the Upper Triassic Dockum Group of Howard County, Texas, with revisions to the genera *Lasalichthys* and *Synorichthys*"](https://par.nsf.gov/servlets/purl/10082031). *Journal of Vertebrate Paleontology*. **38** (5) e1513009. [Bibcode](/source/Bibcode_(identifier)):[2018JVPal..38E3009G](https://ui.adsabs.harvard.edu/abs/2018JVPal..38E3009G). [doi](/source/Doi_(identifier)):[10.1080/02724634.2018.1513009](https://doi.org/10.1080%2F02724634.2018.1513009). [ISSN](/source/ISSN_(identifier)) [0272-4634](https://search.worldcat.org/issn/0272-4634). [S2CID](/source/S2CID_(identifier)) [92328870](https://api.semanticscholar.org/CorpusID:92328870).

1. ^ [***a***](#cite_ref-:0_3-0) [***b***](#cite_ref-:0_3-1) [***c***](#cite_ref-:0_3-2) [***d***](#cite_ref-:0_3-3) [***e***](#cite_ref-:0_3-4) [***f***](#cite_ref-:0_3-5) Kim, Su-Hwan; Lee, Yuong-Nam; Park, Jin-Young; Lee, Sungjin; Lee, Hang-Jae (2020-04-01). ["The first record of redfieldiiform fish (Actinopterygii) from the Upper Triassic of Korea: Implications for paleobiology and paleobiogeography of Redfieldiiformes"](https://www.sciencedirect.com/science/article/pii/S1342937X19303211). *Gondwana Research*. **80**: 275–284. [Bibcode](/source/Bibcode_(identifier)):[2020GondR..80..275K](https://ui.adsabs.harvard.edu/abs/2020GondR..80..275K). [doi](/source/Doi_(identifier)):[10.1016/j.gr.2019.11.008](https://doi.org/10.1016%2Fj.gr.2019.11.008). [ISSN](/source/ISSN_(identifier)) [1342-937X](https://search.worldcat.org/issn/1342-937X). [S2CID](/source/S2CID_(identifier)) [213571269](https://api.semanticscholar.org/CorpusID:213571269).

1. **[^](#cite_ref-4)** Xu, Guang-Hui (2021). ["A new stem-neopterygian fish from the Middle Triassic (Anisian) of Yunnan, China, with a reassessment of the relationships of early neopterygian clades"](https://www.researchgate.net/publication/342509835). *Zoological Journal of the Linnean Society*. **191** (2): 375–394. [doi](/source/Doi_(identifier)):[10.1093/zoolinnean/zlaa053](https://doi.org/10.1093%2Fzoolinnean%2Fzlaa053).

1. ^ [***a***](#cite_ref-:3_5-0) [***b***](#cite_ref-:3_5-1) Lombardo, Cristina (2013). ["A new basal actinopterygian fish from the Late Ladinian of Monte San Giorgio (Canton Ticino, Switzerland)"](https://sjg.springeropen.com/articles/10.1007/s00015-013-0125-9). *[Swiss Journal of Geosciences](/source/Swiss_Journal_of_Geosciences)*. **106** (2): 219–230. [doi](/source/Doi_(identifier)):[10.1007/s00015-013-0125-9](https://doi.org/10.1007%2Fs00015-013-0125-9). [ISSN](/source/ISSN_(identifier)) [1661-8734](https://search.worldcat.org/issn/1661-8734). [S2CID](/source/S2CID_(identifier)) [129121812](https://api.semanticscholar.org/CorpusID:129121812).

1. **[^](#cite_ref-6)** Gibson, Sarah Z. (2018-09-03). ["A new species of Lasalichthys (Actinopterygii, Redfieldiiformes) from the Upper Triassic Dockum Group of Howard County, Texas, with revisions to the genera Lasalichthys and Synorichthys"](https://www.tandfonline.com/doi/full/10.1080/02724634.2018.1513009). *Journal of Vertebrate Paleontology*. **38** (5) e1513009. [doi](/source/Doi_(identifier)):[10.1080/02724634.2018.1513009](https://doi.org/10.1080%2F02724634.2018.1513009). [ISSN](/source/ISSN_(identifier)) [0272-4634](https://search.worldcat.org/issn/0272-4634).

v t e Neopterygii Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Class: Actinopterygii Clade: Actinopteri Actinopterygii see Actinopterygii Neopterygii see below↓ Neopterygii Neopterygii †Besania †Boreichthys †Caelatichthys †Cephaloxenus †Chrotichthys †Dollopterus †Frodoichthys †Gimlichthys †Habroichthys †Hulettia †Pristisomus †Tungusichthys †Venusichthys †Zeuchthiscus †Bobasatraniiformes? †Guildayichthyidae? †Pholidopleuriformes? Arctosomus Australosomus Gracilignathichthys Macroaethes Pholidopleurus †Redfieldiiformes? Atopocephala Brookvalia Calaichthys Cionichthys Daedalichthys Denwoodichthys Dictyopyge Endemichthys Geitonichthys Helichthys Hiascoactinus Ischnolepis Lasalichthys Leighiscus Mauritanichthys Molybdichthys Pacorichthys Phlyctaenichthys Redfieldius Sakamenichthys Schizurichthys Sinkiangichthys? †Platysiagidae Caelatichthys? Helmolepis Platysiagum †Polzbergiiformes Hydropessum? Cleithrolepididae Cleithrolepidina Cleithrolepis Polzbergiidae Felberia Luopingichthys? Polzbergia Serrolepis Stoppania †Colobodontidae Chaohuperleidus? Colobodus Crenilepis Dactylolepis? Engycolobodus? Feroxichthys Gabanellia? Nephrotus? †Perleididae Aetheodontus? Alvinia? Chaohuperleidus? Ctenognathichthys? Daninia Diandongperleidus? Dipteronotus? Endennia? Eoperleidus Fuyuanperleidus? Luopingperleidus? Manlietta Megaperleidus? Meidiichthys Meridensia? Moradebrichthys? Paraperleidus Peltoperleidus? Perleidus Plesiofuro? Plesioperleidus Procheirichthys? Teffichthys? Tripelta †Louwoichthyiformes Peltoperleidus? Louwoichthyidae Ctenognathichthys? Louwoichthys Luopingichthys? Pseudobeaconiidae Anatoia Caminchaia Dipteronotus? Echentaia Mendocinichthys Pasambaya Pseudobeaconia †Luganoiiformes Altisolepis? Fuyuanperleidus? Luganoia †Peltopleuriformes Habroichthys? Peltopleuridae Altisolepis? Nannolepis Peltopleurus Placopleurus Thoracopteridae Gigantopterus Italopterus Peripeltopleurus Potanichthys Thoracopterus Wushaichthys †Pycnodontiformes see Pycnodontiformes Holostei Ginglymodi see Ginglymodi includes gars Halecomorphi see Halecomorphi includes bowfin Teleostei see Teleostei includes the majority of modern fish

Taxon identifiers Redfieldiiformes Wikidata: Q19839167 Paleobiology Database: 65497

Authority control databases: National Israel

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Adapted from the Wikipedia article [Redfieldiiformes](https://en.wikipedia.org/wiki/Redfieldiiformes) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Redfieldiiformes?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.