Pycnodontiformes
Pycnodontiformes Temporal range:
| |
---|---|
Pycnodontiform diversity | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Subclass: | Neopterygii |
Order: | †Pycnodontiformes Berg, 1937 |
Families | |
Pycnodontiformes is an extinct order of primarily marine bony fish. The group first appeared during the Late Triassic and disappeared during the Eocene. The group has been found in rock formations in Africa, Asia, Europe, North and South America.[1] They were small to middle-sized fish, generally with laterally-compressed deep bodies, some with almost circular outlines,[2] adapted for manuverability in reef-like environments, though the group was morphologically diverse.[3] Most, but not all members of the groups had jaws with round and flattened teeth,[4] well adapted to crush food items (durophagy), such as echinoderms, crustaceans and molluscs.[3] Some pyncodontiformes developed piranha like teeth used for eating flesh.[5][6] Most species inhabited shallow marine reef environments, while a handful of species lived in freshwater or brackish conditions. While rare during the Triassic and Early-Middle Jurassic, Pycnodontiformes became abundant and diverse during the Late Jurassic, exhibiting a high but relatively static diversity during the Early Cretaceous. At the beginning of the Late Cretaceous they reached their apex of morphological and species diversity (much of this due to fossils found in Lebanon, such as Gebrayelichthyidae and Ichthyoceros), after which they began to gradually decline, with a more sudden decline at the end of the Cretaceous due to the collapse of reef ecosystems, finally becoming extinct during the Eocene. They are considered to belong to the Neopterygii, but their relationship to other members of that group is uncertain.[3]
Evolution and diversity
Pycnodontiforms first appeared in the
They evolved such different jaw structures to avoid potential competition with other groups of durophagous neopterygians, such as the
The fossil record of pycnodonts spans 175 million years, from the Triassic to the
Taxonomy
- Order Pycnodontiformes (Berg, 1937)[8][9]
- Genus ?Acrorhinichthys Taverne & Capasso, 2015
- Genus ?Archaeopycnodon Sanchez & Benedetto, 1980
- Genus ?Athrodon le Sauvage 1880 non Osborn, 1887
- Genus ?Callodus Thurmond, 1974
- Genus ?Cosmodus le Sauvage, 1879 [Glossodus Costa, 1851 non Agassiz, 1828 ex Spix & Agassiz, 1829 non McCoy, 1848]
- Genus ?Ellipsodus Cornuel, 1877
- Genus ?Grypodon Hay, 1899 [Ancistrodon Dames, 1883 non De Beauvois, 1799 non Roemer, 1852 non Wagler, 1830]
- Genus ?Mercediella Koerber, 2012 [Camposichthys Figueiredo & Silva-Santos, 1991 non Travassos, 1946 non Whitley, 1953]
- Genus ?Piranhamesodon Kölbl-Ebert et al., 2018
- Genus ?Pseudopycnodus Taverne, 2003
- Genus ?Tergestinia Capasso, 2000
- Genus ?Thurmondella Thurmond, 1974 non [Paramicrodon Thurmond, 1974 non de Meijere, 1913]
- Genus ?Uranoplosus le Sauvage, 1879
- Genus ?Woodthropea Swinnerton, 1925
- Family ?Hadrodontidae Thurmond & Jones, 1981
- Family ?Gebrayelichthyidae Nursall & Capasso, 2004
- Genus Gebrayelichthys Nursall & Capasso, 2004
- Genus Maraldichthys Taverne & Capasso, 2014
- Family ?Gladiopycnodontidae Taverne & Capasso, 2013
- Genus Arduafrons Frickhinger, 1991
- Genus Eomesodon Woodward, 1918
- Genus Gladiopycnodus Taverne & Capasso, 2013
- Genus Joinvillichthys Taverne & Capasso, 2014
- Genus Micropycnodon Hibbard & Graffham, 1945 [Pycnomicrodon Hibbard & Graffham, 1941 non Hay, 1916]
- Genus Monocerichthys Taverne & Capasso, 2013
- Genus Pankowskichthys Taverne & Capasso, 2014
- Genus Paramesturus Taverne, 1981
- Genus Rostropycnodus Taverne & Capasso, 2013
- Genus Stenoprotome Hay, 1903
- Family Mesturidae Nursall, 1996
- Genus Mesturus Wagner, 1862
- Family Gyrodontidae Berg, 1940
- Genus Gyrodus Agassiz, 1833
- Family Brembodontidae Tintori, 1981 [Brembodidae; Gibbodontidae Tintori, 1981]
- Family Coccodontidae Berg, 1940 [Trewavasiidae Nursall, 1996]
- Genus Coccodus Pictet, 1850
- Genus Corusichthys Taverne & Capasso, 2014
- Genus Hensodon Kriwet, 2004
- Genus Ichthyoceros Gayet, 1984 [10]
- Genus Paracoccodus Taverne & Capasso, 2014
- Genus Trewavasia White & Moy-Thomas, 1941 [Xenopholis Davis, 1887 non Peters, 1869; Xenopholoides Fowler, 1958] [10]
- Family Pycnodontidae Agassiz, 1833 corrig. Bonaparte, 1845 [Nursalliidae Bloy, 1987; Sphaerodontidae Giebel, 1846; Palaeobalistidae Blot, 1987; Proscinetidae Gistel, 1848; Gyronchidae]
- Genus Abdobalistum Poyato-Ariza & Wenz, 2002
- Genus Anomiophthalmus Costa, 1856
- Genus Anomoeodus Forir, 1887
- Genus Acrotemnus Agassiz 1836,
- Genus Akromystax Poyato-Ariza & Wenz, 2005
- Genus Coelodus Heckel, 1854
- Genus Flagellipinna Cawley & Kriwet, 2019
- Genus Macropycnodon Shimada, Williamson & Sealey, 2010
- Genus Macromesodon Blake 1905 non Lehman, 1966 [Mesodon Wagner, 1851 non Rafinesque, 1821; Gyronchus Agassiz, 1839; Apomesodon Poyato-Ariza & Wenz, 2002]
- Genus Neoproscinetes De Figueiredo & Silva Santos, 1990
- Genus Njoerdichthys Cawley, Lehmann, Wiese & Kriwet, 2020[7]
- Genus Nursallia Blot, 1987
- Genus Ocloedus Poyato-Ariza & Wenz, 2002
- Genus Oropycnodus Poyato-Ariza & Wenz, 2002
- Genus Palaeobalistum Taverne et al., 2015
- Genus Paranursallia Taverne et al., 2015
- Genus Phacodus Dixon, 1850
- Genus Polazzodus Poyoto-Ariza, 2010
- Genus Polygyrodus White, 1927
- Genus Potiguara Machado & Brito, 2006
- Genus Microdon Agassiz, 1833 non Meigen, 1803 non Fritsch, 1876 non Conrad, 1842 non Gistl, 1848 non Dixon, 1850; PolypsephisHay, 1899]
- Genus Pycnomicrodon Hay 1916 non Hibbard & Graffham, 1941
- Genus Pycnodus Agassiz, 1833
- Genus Rhinopycnodus Taverne & Capasso, 2013
- Genus SphaerodusAgassiz, 1833
- Genus Sphaeronchus Stinton & Torrens, 1967
- Genus Stenamara Poyato-Ariza & Wenz, 2000
- Genus Stemmatias Hay, 1899 [Stemmatodus St. John & Worthen, 1875 non Heckel, 1854 non]
- Genus Stemmatodus Heckel, 1854 non St. John & Worthen, 1875 non
- Genus Sylvienodus Poyato-Ariza & Wenz, 2013
- Genus Tamanja Wenz, 1989
- Genus Tepexichtys Applegate, 1992
- Genus Thiollierepycnodus Ebert, 2020
- Genus Tibetodus Young & Liu, 1954
- Genus Turbomesodon Poyato-Ariza & Wenz, 2004 [Macromesodon Lehman, 1966 non Blake, 1905]
- Genus Typodus Quenstedt, 1858
- Family incertae sedis
- Genus Agassizilia Cooper and Martill, 2020[11]
- Genus Neomesturus Cooper and Martill, 2020[12]
Phylogeny
The phylogenetic relation between pycnodonts and other actinopterygians is uncertain. The difficulty of placing them on a phylogenetic tree arises from the fact that they are a clade defined by a high number of autapomorphies (characteristics shared by a single taxon), which makes them easy to identify, but also makes the study of their relations with other actinopterygians difficult, since characteristics shared by other groups might be obfuscated by the immense amount of features and diversity of pycnodonts.[13]
Previously, Pycnodontiformes where proposed to be a sister group of
Actinopterygii |
| ||||||||||||||||||
As a means to avoid potential competition, the families of Pycnodontiforms evolved different body and jaw shapes, resulting in a highly diverse group.[3] Pycnodontidae were the most advanced group, being the largest family, comprising 26 known described genera.[14]
Pycnodontiformes | |
References
- ^ "Pycnodontiformes". Palaeos vertebrates. Archived from the original on 25 October 2008. Retrieved 27 July 2009.
- ^ "Pycnodontid fishes from the Kansas Cretaceous". Oceans of Kansas. 16 April 2009. Retrieved 29 July 2009.
- ^ PMID 33614003.
- ISBN 978-1-893882-18-8.
- S2CID 53045425.
- PMID 28754956.
- ^ a b Cawley, John; Lehnmann, Jens; Wiese, Frank; Kriwet, Jürgen (2020). "Njoerdichthys dyckerhoffi gen. et sp. nov. (Pycnodontiformes, lower Turonian) northward migration caused by the Cretaceous Thermal Maximum". Cretaceous Research. 116.
- ISBN 9781118342336.
- ^ van der Laan, Richard (2016). "Family-group names of fossil fishes".
{{cite journal}}
: Cite journal requires|journal=
(help) - ^ a b L. Taverne; L. Capasso (2014). "Ostéologie et phylogénie des Coccodontidae, une famille remarquable de poissons Pycnodontiformes du Crétacé supérieur marin du Liban, avec la description de deux nouveaux genres". Palaeontos. 25. Archived from the original on 2017-07-05. Retrieved 2016-07-05.
- .
- ^ Cooper, S.L.A. and Martill, D.M. (2020). "Pycnodont fishes (Actinopterygii: Pycnodontiformes) from the Upper Cretaceous (lower Turonian) Akrabou Formation of Asfla, Morocco" Cretaceous Research 116, 104607
- ^ a b Poyato-Ariza, Francisco (2015). "Studies on Pycnodontid fishes (I): Evaluation of their phylogenetic position among actinopterygians". Rivista Italiana di Paleontologia e Stratigrafia. 121 (3): 329–343.
- ^ Ebert, Martin (2020). "A new genus of Pycnodontidae (Actinopterygii) from the Upper Jurassic of France and Germany, included in a phylogeny of Pycnodontiformes". Zoological Journal of the Linnean Society. 188 (2): 434–454.
- Capasso, Luigi (2021). "Pycnodonts: An overview and new insights in the Pycnodontomorpha Nursall, 2010". Occasional Paper of the University Museum of Chieti, Monographic Publication, 1: 1–223.
- Sepkoski, Jack (2002). "A compendium of fossil marine animal genera". Bulletins of American Paleontology. 364: 560. Retrieved 2011-05-17.