Pycnodontiformes

Last updated

Pycnodontiformes
Temporal range: Late Triassic–Eocene
Pycnodont diversity.png
Pycnodontiform diversity
Scientific classification OOjs UI icon edit-ltr.svg
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]

Contents

Evolution and diversity

Macromesodon gibbosus (formerly species of Eomesodon), a species of Brembodontidae from the Jurassic Solnhofen Limestone. Eomesodon gibbosus 723.jpg
Macromesodon gibbosus (formerly species of Eomesodon), a species of Brembodontidae from the Jurassic Solnhofen Limestone.

Pycnodontiforms first appeared in the Late Triassic, alongside other successful groups of early neopterygians such as dapediiforms. A contributor for this early radiation of neopterygians was their effectiveness at adapting to different diets. Pycnodonts from the Late Triassic Zorzino Limestone in Italy had short and stout jaws with big crushing teeth for eating hard-shelled prey, while other actinopterygians like saurichthyids and birgeriids mainly occupied top predator piscivorous niches. They originated from marine habitats, specializing for manoeuverability in reef environments, but developed a variety of adaptations during the Mesozoic that enable them to pursue new diets and habitats, such as estuaries and freshwaters. Only a few species adapted for open waters, like those of the family Gyrodontidae. [3] In the Western Tethys, pycnodonts have always had a high species diversity. This stable environment, alongside its favorable climate conditions, supported the dispersal patterns within basal pycnodontids. [7]

They evolved such different jaw structures to avoid potential competition with other groups of durophagous neopterygians, such as the Dapediiformes and the Ginglymodi. Furthermore, their improved jaw performance also differentiated the pycnodonts from these neopterygians in that they allowed them to feed on tougher prey, while their increase in size allowed them to prey on larger items or specialise on a few species. Their families also differentiated amongst themselves in body and jaw shape, implying that they were more diverse in diet and habitat than previously thought. [3]

The fossil record of pycnodonts spans 175 million years, from the Triassic to the Eocene, existing longer than non-avian dinosaurs. Their early record is incomplete, having only three genera from the Late Triassic, all with complete specimens. Whereas from the Early to Mid-Jurassic there are only isolated teeth and jaws, and rarely a few exceptions for better, but still incomplete, fossils. By the Late Jurassic Pycnodontiforms became more common in the fossil record, a fact that relates to the presence of Lagerstätten, providing articulated fossils. This growth continues and, by the Late Cretaceous, they experience a peak in diversity during the Cenomanian. They were severely struck by the K/Pg Extinction and afterwards their diversity shrunk, having never achieved pre-extinction levels of diversity, eventually going extinct by the Late Eocene (Priabonian). [3]

Taxonomy

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. [15]

Previously, Pycnodontiformes where proposed to be a sister group of Teleostei or Teleosteomorpha, but in a 2015 analysis by Poyato-Ariza, they turned up as the most basal Neopterygii among the others of the group included, those being Lepisosteiformes, Semionotiformes, Macrosemiiformes, Halecomorphi and Teleostei. [15]

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. [16]

Pycnodontiformes

Related Research Articles

<span class="mw-page-title-main">Gonorynchiformes</span> Order of fishes

The Gonorynchiformes are an order of ray-finned fish that includes the important food source, the milkfish, and a number of lesser-known types, both marine and freshwater.

<span class="mw-page-title-main">Chanidae</span> Family of fishes

Chanidae is a family of fishes which has a number of fossil genera and one monotypic extant genus which contains the milkfish.

<span class="mw-page-title-main">Amiiformes</span> Order of fishes

The Amiiformes order of fish has only two extant species, the bowfins: Amia calva and Amia ocellicauda, the latter recognized as a separate species in 2022. These Amiiformes are found in the freshwater systems of North America, in the United States and parts of southern Canada. They live in freshwater streams, rivers, and swamps. The order first appeared in the Triassic, and the extinct members include both marine and freshwater species, many of which are morphologically disparate from bowfins, such as the caturids.

<span class="mw-page-title-main">Semionotiformes</span> Extinct order of fishes

Semionotiformes is an order of ray-finned fish known from the Middle Triassic (Anisian) to the Late Cretaceous (Maastrichtian). Their closest living relatives are gars (Lepisosteidae), with both groups belonging to the clade Ginglymodi within the Holostei. The group includes both freshwater (Semionotidae) and marine adapted forms. Many members of the family Macrosemiidae, had elongated dorsal fins, often associated with an adjacent area of skin which was free of scales. These fins were likely undulated for use in precision swimming. The body morphology of macrosemiids suggests that they were slow swimmers who were capable of maneuvering around complex topography, such as reef environments.

<span class="mw-page-title-main">Elopiformes</span> Order of fishes

The Elopiformes are the order of ray-finned fish including the tarpons, tenpounders, and ladyfish, as well as a number of extinct types. They have a long fossil record, easily distinguished from other fishes by the presence of an additional set of bones in the throat.

<i>Pycnodus</i> Extinct genus of fishes

Pycnodus is an extinct genus of ray-finned fish from the Eocene period. It is wastebasket taxon, although many fossils from Jurassic or Cretaceous are assigned to this genus, only Eocene species, P. apodus is valid. As its name suggests, it is the type genus of Pycnodontiformes.

Anomoeodus is an extinct genus of prehistoric marine ray-finned fish belonging to the family Pycnodontidae. This genus primarily lived during the mid-to-late Cretaceous period, ranging from the Albian to the very end of the Maastrichtian age, and possibly into the Danian. The first fossils of Anomoeodus were described by Louis Agassiz in 1833, although they were described under Pycnodus. Some studies have recovered it as a wastebasket taxon.

<i>Coelodus</i> Extinct genus of fishes

Coelodus is an extinct genus of marine and possibly freshwater pycnodont fish. It contains only one definitive species, C. saturnusHeckel, 1854, from the Late Cretaceous of Slovenia. Other species from the Late Jurassic to the Eocene have also been attributed to this genus based on isolated dental elements, but their assignment to Coelodus is uncertain, and this genus likely represents a non-monophyletic wastebasket taxon. A potential diagnostic trait is a prearticular tooth row with three regular highly elongated teeth.

<span class="mw-page-title-main">Crossognathiformes</span> Extinct order of ray-finned fishes

Crossognathiformes is an extinct order of ray-finned fish that lived from the Late Jurassic to the Eocene. Its phylogenetic placement is disputed; some authors have recovered it as part of the teleost stem group, while others place it in a basal position within crown group Teleostei.

This list of fossil fishes described in 2014 is a list of new taxa of placoderms, fossil cartilaginous fishes and bony fishess of every kind that have been described during the year 2014, as well as other significant discoveries and events related to paleontology of fishes that occurred in the year 2014. The list only includes taxa at the level of genus or species.

<span class="mw-page-title-main">Pycnodontidae</span> Extinct family of fishes

Pycnodontidae is an extinct family of ray-finned fishes, ranging from the Jurassic period until the Eocene. It was the largest and most derived family of the successful Mesozoic fish order Pycnodontiformes, and the only member of it to survive into the Cenozoic.

<span class="mw-page-title-main">Gebrayelichthyidae</span> Extinct family of fishes

Gebrayelichthyidae is a family of extinct pycnodontid fish, with a superficially shrimpfish-like appearance that lived during the lower Cenomanian.

This list of fossil fish described in 2018 is a list of new taxa of jawless vertebrates, placoderms, acanthodians, fossil cartilaginous fish, bony fish, and other fish of every kind that are scheduled to be described during the year 2018, as well as other significant discoveries and events related to paleontology of fish that are scheduled to occur in 2018.

<span class="mw-page-title-main">Ginglymodi</span> Clade of ray-finned fishes

Ginglymodi is a clade of ray-finned fish containing modern-day gars (Lepisosteidae) & their extinct relatives in the order Lepisosteiformes, the extinct orders Semionotiformes and Kyphosichthyiformes, and various other extinct taxa. Ginglymodi is one of the two major subgroups of the infraclass Holostei, the other one being Halecomorphi, which contains the bowfin and eyespot bowfin and their fossil relatives.

<span class="mw-page-title-main">Dapediidae</span> Extinct family of ray-finned fishes

Dapediidae is an extinct family of neopterygian ray-finned fish that lived from the Middle Triassic to Late Jurassic. It is the only family of the order Dapediiformes. Its members were historically placed within the ginglymodian family Semionotidae, but were moved to their own family in 1966.

Agassizilia is an extinct genus of both freshwater and marine pycnodont fishes from the mid-late Cretaceous (Albian-Turonian). The genus contains two species: A. erfoudina from freshwater deposits of the Kem Kem Group in south-east Morocco and A. barberi of the marine deposits of the Marlbrook Marl of Arkansas, US. The genus is named after paleontologist Louis Agassiz.

<span class="mw-page-title-main">Lepidotidae</span> Extinct family of fish

Lepidotidae is an extinct family of fish, known from the Jurassic and Cretaceous periods. Most species were originally assigned to the genus Lepidotes which was long considered a wastebasket taxon. Cladistic analysis has indicated that they are close relatives of gars, with both being members of the order Lepisosteiformes. Members of the family are known from both marine and freshwater environments. Their bulky body morphology and small median fins suggests that they were slow-moving fish that were capable of performing fine movements in order to grasp prey. Lepidotes sensu stricto had peg-like grasping marginal teeth and crushing palatal teeth, and is known to have consumed small crustaceans, while Scheenstia had low rounded crushing marginal teeth, indicating a durophagous diet.

<i>Gebrayelichthys</i> Extinct genus of Pycnodontiform fish

Gebrayelichthys is a genus of pycnodontiform fish of the family Gebrayelichthyidae. It comprises two species, Gebrayelichthys uyenoi and Gebrayelichthys verticalis. Their extremely deep body shape is unique among known fishes, only comparable to some Paleogene tetraodontiforms, and suggests an ostraciiform locomotion.

<span class="mw-page-title-main">Neoproscinetes</span> Extinct genus of fishes

Neoproscinetes is a genus of extinct pycnodontid fish from the Cretaceous Santana Formation of Brazil. Fossils of this species have also been discovered in the Riachuelo Formation.

<i>Scalacurvichthys</i> Genus of pycnotontinae fish from the Late Cretaceous

Scalacurvichthys is an extinct genus of pycnodontine pycnodontiform fish from the Amminadav Formation or Bet-Meir Formation in the West Bank; Palestine. The type species is S. naishi, only known from the holotype.

References

  1. ↑ "Pycnodontiformes". Palaeos vertebrates. Archived from the original on 25 October 2008. Retrieved 27 July 2009.
  2. ↑ "Pycnodontid fishes from the Kansas Cretaceous". Oceans of Kansas. 16 April 2009. Retrieved 29 July 2009.
  3. 1 2 3 4 5 6 7 Cawley, John J.; Marramà, Giuseppe; Carnevale, Giorgio; Villafaña, Jaime A.; López‐Romero, Faviel A.; Kriwet, Jürgen (February 2021). "Rise and fall of †Pycnodontiformes: Diversity, competition and extinction of a successful fish clade". Ecology and Evolution. 11 (4): 1769–1796. doi:10.1002/ece3.7168. ISSN   2045-7758. PMC   7882952 . PMID   33614003.
  4. ↑ McMenamin, M. A. S. (2009). Paleotorus: The Laws of Morphogenetic Evolution. Meanma Press. ISBN   978-1-893882-18-8.
  5. ↑ Kölbl-Ebert, Martina; Ebert, Martin; Bellwood, David R.; Schulbert, Christian (2018-11-05). "A Piranha-like Pycnodontiform Fish from the Late Jurassic". Current Biology. 28 (21): 3516–3521.e2. doi: 10.1016/j.cub.2018.09.013 . ISSN   0960-9822. PMID   30344113. S2CID   53045425.
  6. ↑ Vullo, Romain; Cavin, Lionel; Khalloufi, Bouziane; Amaghzaz, Mbarek; Bardet, Nathalie; Jalil, Nour-Eddine; Jourani, Essaid; Khaldoune, Fatima; Gheerbrant, Emmanuel (2017-07-28). "A unique Cretaceous–Paleogene lineage of piranha-jawed pycnodont fishes". Scientific Reports. 7 (1): 6802. doi:10.1038/s41598-017-06792-x. ISSN   2045-2322. PMC   5533729 . PMID   28754956.
  7. 1 2 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.
  8. ↑ Nelson, Joseph S.; Grande, Terry C.; Wilson, Mark V. H. (2016). Fishes of the World (5th ed.). John Wiley & Sons. ISBN   9781118342336.
  9. ↑ van der Laan, Richard (2016). "Family-group names of fossil fishes".{{cite journal}}: Cite journal requires |journal= (help)
  10. 1 2 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.
  11. ↑ Cooper, Samuel L. A.; Martill, David M. (2020-08-01). "A diverse assemblage of pycnodont fishes (Actinopterygii, Pycnodontiformes) from the mid-Cretaceous, continental Kem Kem Group of south-east Morocco". Cretaceous Research. 112: 104456. Bibcode:2020CrRes.11204456C. doi:10.1016/j.cretres.2020.104456. ISSN   0195-6671.
  12. ↑ Özdikmen, H. (2009-01-06). "Texasensis nom. nov., a new name for the preoccupied fossil fish genus Callodus Thurmond, 1974 (Osteichthyes: Pycnodontiformes)". Texasensis Nom. Nov., A New Name for the Preoccupied Fossil Fish Genus Callodus Thurmond, 1974 (Osteichthyes: Pycnodontiformes). 4 (2): 616. ISSN   1306-3022.
  13. ↑ Cooper, Samuel L.A.; Martill, David M. (August 2020). "A diverse assemblage of pycnodont fishes (Actinopterygii, Pycnodontiformes) from the mid-Cretaceous, continental Kem Kem Group of south-east Morocco". Cretaceous Research. 112: 104456. doi:10.1016/j.cretres.2020.104456.
  14. ↑ 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
  15. 1 2 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.
  16. ↑ 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.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.