Atractosteus

Atractosteus
Temporal range:
~SantonianPresent, 86.3–0 Ma[1]
Alligator gar
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Clade: Ginglymodi
Order: Lepisosteiformes
Family: Lepisosteidae
Genus: Atractosteus
(Rafinesque, 1820)
Type species
Esox spatula
Species

See text

Synonyms[2][3]
  • Lepisosteus (Atractosteus) Rafinesque 1820
  • Litholepis Rafinesque 1818
Atractosteus atrox

Atractosteus is a genus of gars in the family Lepisosteidae, with three extant species. It is one of two surviving gar genera alongside Lepisosteus.[4]

The three surviving species are all widely separated from one another, with A. spatula being found in the south-central United States, A. tropicus in southern Mexico and Central America, and A. tristoechus in Cuba.[4] Although generally inhabiting fresh water, they are tolerant of marine conditions.

Evolution

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The genus first appeared during the Santonian stage of the Late Cretaceous, having diverged from Lepisosteus earlier in the Cretaceous.[4] It quickly achieved a widespread distribution throughout the rest of the Cretaceous, being known from North America, South America and Europe.[5][6] Atractosteus survived the Cretaceous-Paleogene extinction event, with one articulated fossil of the species A. grandei being recovered from strata dated to just a few thousand years after the extinction event, making it the oldest known articulated vertebrate fossil from the Cenozoic.[7] It was found throughout North America and Europe during the Paleogene, but by the Neogene this had shrunk to only certain parts of North America, where it is still found today.[4]

Systematics

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Lepisosteidae

Species

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Extant species

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Image Scientific name Common name Distribution
Atractosteus spatula Lacépède, 1803 Alligator gar Southern United States
Atractosteus tristoechus Bloch & J. G. Schneider, 1801 Cuban gar Western Cuba and the Isla de la Juventud
Atractosteus tropicus T. N. Gill, 1863 Tropical gar Southern Mexico to Costa Rica

Fossils

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Former fossil genera:

References

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  1. ^ Szabó, M.; Gulyás, P.; Ősi, A. (2016). "Late Cretaceous (Santonian) Atractosteus (Actinopterygii, Lepisosteidae) remains from Hungary (Iharkút, Bakony Mountains)". Cretaceous Research: 239–252. doi:10.1016/j.cretres.2015.12.002.
  2. ^ Froese, R.; Pauly, D. (2017). "Lepisosteidae". FishBase version (02/2017). Retrieved 18 May 2017.
  3. ^ Van Der Laan, Richard; Eschmeyer, William N.; Fricke, Ronald (11 November 2014). "Family-group names of Recent fishes". Zootaxa. 3882 (1): 1–230. doi:10.11646/zootaxa.3882.1.1. PMID 25543675.
  4. ^ a b c d Doran Brownstein, Chase; Yang, Liandong; Friedman, Matt; Near, Thomas J (2022-12-20). "Phylogenomics of the Ancient and Species-Depauperate Gars Tracks 150 Million Years of Continental Fragmentation in the Northern Hemisphere". Systematic Biology. 72 (1): 213–227. doi:10.1093/sysbio/syac080. ISSN 1063-5157.
  5. ^ Alves, Yuri Modesto; Montefeltro, Felipe Chinaglia; Cidade, Giovanne M. (2021-05-01). "New occurrences of Atractosteus (Ginglymodi: Lepisosteoidea: Lepisosteidae) from the Bauru Group (Upper Cretaceous, Brazil) and paleobiogeographic implications". Cretaceous Research. 121: 104735. doi:10.1016/j.cretres.2020.104735. ISSN 0195-6671.
  6. ^ Szabó, Márton; Gulyás, Péter; Ősi, Attila (2016-05-01). "Late Cretaceous (Santonian) Atractosteus (Actinopterygii, Lepisosteidae) remains from Hungary (Iharkút, Bakony Mountains)". Cretaceous Research. 60: 239–252. doi:10.1016/j.cretres.2015.12.002. ISSN 0195-6671.
  7. ^ Brownstein, Chase Doran; Lyson, Tyler R. (2022). "Giant gar from directly above the Cretaceous–Palaeogene boundary suggests healthy freshwater ecosystems existed within thousands of years of the asteroid impact". Biology Letters. 18 (6). doi:10.1098/rsbl.2022.0118. ISSN 1744-957X. PMC 9198771. PMID 35702983.
  8. ^ Cavin, Lionel; Martin, Michel; Valentin, Xavier (1996). "Occurrence of Atractosteus africanus (actinopterygii, lepisosteidae) in the early Campanien of Ventabren (Bouches-du-Rhône, France). Paleobiogeographical implications". Revue de Paléobiologie. 15 (1): 1–7.
  9. ^ Brownstein, Chase Doran; Lyson, Tyler R. (2022). "Giant gar from directly above the Cretaceous–Palaeogene boundary suggests healthy freshwater ecosystems existed within thousands of years of the asteroid impact". Biology Letters. 18 (6): 20220118. doi:10.1098/rsbl.2022.0118. PMC 9198771. PMID 35702983.