Enchodus

Enchodus is an extinct genus of aulopiform ray-finned fish related to lancet- and lizardfish. Species of Enchodus flourished during the Late Cretaceous, and survived the Cretaceous–Paleogene extinction event, persisting into the late Eocene.

Enchodus Temporal range: Albian-Priabonian ~112.6–37.2 Ma PreꞒ Ꞓ O S D C P T J K Pg N
E. petrosus mounted skeleton cast in the Rocky Mountain Dinosaur Resource Center in Woodland Park, Colorado
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Subclass:	Neopterygii
Order:	Aulopiformes
Suborder:	Aleposauroidei
Family:	†Enchodontidae
Genus:	Enchodus Agassiz, 1835
Species
E. amicrodus[1] E. annectens Woodward 1901[2] E. brevis Chalifa 1989[2] E. dirus Leidy 1857[2] E. elegans Dartevelle & Casier 1949[3] E. faujasi Agassiz 1843[2] E. ferox Leidy 1855[2] E. gladiolus Cope 1872[2] E. gracilis Der Marck 1858[2] E. lamberti Arambourg and Joleaud 1943[2] E. lemonnieri Dello 1893[2] E. lewesiensis Mantell 1822[2] E. libyus[4] E. longidens Pictet 1850[2] E. longipectoralis Schaeffer 1947[2] E. major Davis 1887[2] E. marchesettii Kramberger 1895[2] E. mecoanalis Forey et al. 2003[2] E. oliveirai Maury 1930[2] E. parvus E. petrosus Cope 1874[2] E. pulchellus Woodward 1901 [2] E. saevus Hay 1903[2] E. semistriatus Marsh 1869[2] E. shumardi Leidy 1856[2] E. subaequilateralis Cope 1885[2] E. tineidae Holloway et al. 2017[5] E. venator Arambourg 1954[2] E. zipapanensis Fielitz and González-Rodríguez 2010[2]

Taxonomy

Species of Enchodus are generally classified into two different clades, the North American and the Mediterranean. It has been proposed that this distinction is the result of several isolated events between the two populations over the Late Cretaceous.[5]

Enchodus[5]

Enchodus   E. marchesettii         Parenchodus     E. brevis     E. lewesiensis             E. gracilis       E. venator     E. shumardi           E. petrosus     E. zipapanensis     E. faujasi       E. gladiolus       E. tineidae     E. dirus

Phylogeny of the genus with some species

Description

Enchodus species were small to medium in size. One of the genus' most notable attributes are the large "fangs" at the front of the upper and lower jaws and on the palatine bones, leading to its misleading nickname among fossil hunters and paleoichthyologists, "the saber-toothed herring". These fangs, along with a long sleek body and large eyes, suggest Enchodus was a predatory species.

The largest-known species of Enchodus is E. petrosus, remains of which are common from the Niobrara Chalk, the Mooreville Chalk Formation, the Pierre Shale, and other geological formations deposited within the Western Interior Seaway and the Mississippi Embayment. Large individuals of this species had fangs measuring over 6 centimetres (2.4 in) in length, though the total body length was only about 1.5 metres (4 ft 11 in), giving its skull an appearance somewhat reminiscent of modern deep-sea fishes, such as anglerfish and viperfish. Other species were considerably smaller, some like E. parvus were only some centimeters (a few inches) long.

Despite being a formidable predator, remains of Enchodus are commonly found among the stomach contents of larger predators, including sharks, other bony fish, mosasaurs, plesiosaurs and seabirds such as Baptornis advenus.

Distribution

Enchodus fossils have been found all over the world. In North America, Enchodus remains have been recovered from most US states with fossiliferous Late Cretaceous rocks, including Kansas, Nebraska, Colorado, Alabama, Mississippi, Georgia, Tennessee, Wyoming, Texas, California, North Carolina, and New Jersey. Fossils also have been found in the Aguja and El Doctor Formations of Mexico and the Ashville, Vermillion River and Dinosaur Park Formations, and Brown Bed Member of Canada. The taxon is also known from coeval strata in Africa, the Middle East, Europe, southwest Asia and the Tiupampan Santa Lucía Formation and Maastrichtian El Molino Formation of Bolivia and the Paraíba, Pernambuco and Sergipe states of Brazil.[2]

Gallery

• 
  Restoration of E. petrosus
• 
  E. lewesiensis skull
• 
  Teeth of E. elegans from Khouribga
• 
  Teeth of E. libyus from Khouribga

References

1. The Sabre-Toothed Fish of the Cretaceous
2. Enchodus at Fossilworks.org
3. Global Names Index
4. "Mundo Fosil". Archived from the original on 2014-11-14. Retrieved 2015-05-13.
5. Waymon L. Holloway; Kerin M. Claeson; Hesham M. Sallam; Sanaa El-Sayed; Mahmoud Kora; Joseph J.W. Sertich; Patrick M. O’Connor (2017). "A new species of the neopterygian fish Enchodus from the Duwi Formation, Campanian, Late Cretaceous, Western Desert, central Egypt". Acta Palaeontologica Polonica. 62 (3): 603–611. doi:10.4202/app.00331.2016.

Further reading

• Cope, Edward Drinker (1874): Review of the Vertebrata of the Cretaceous period found west of the Mississippi River. U. S. Geological Survey of the Territories, Bulletin 1(2): 3-48.
• Everhart, Mike (2007): Oceans of Kansas: Enchodus sp. - The Sabre-Toothed Fish of the Cretaceous. Version of 2007-MAY-29. Retrieved 2007-AUG-23.
• Russell, D. A. (1988): A check list of North American Marine Cretaceous vertebrates including fresh water fishes. Occasional Paper of the Tyrrell Museum of Palaeontology #4.
• Davis, Matthew P.; Fielitz, Christopher (2010). "Estimating divergence times of lizardfishes and their allies (Euteleostei: Aulopiformes) and the timing of their deep-sea adaptations". Molecular Phylogenetics and Evolution. 57. doi:10.1016/j.ympev.2010.09.003.

External links

• Media related to Enchodus at Wikimedia Commons
• Introduction to Paleontology