Atractosteus

(Redirected from Litholepis)

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]

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

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

edit

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

edit
Lepisosteidae

Species

edit

Extant species

edit
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

edit

Former fossil genera:

References

edit
  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.