Enchodus

Enchodus
Temporal range: Albian-Maastrichtian
~105–66 Ma
Possible Barremian & Paleogene records
E. petrosus mounted skeleton cast, Rocky Mountain Dinosaur Resource Center
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Division: Teleostei
Order: Aulopiformes
Family: †Enchodontidae
Genus: †Enchodus
Agassiz, 1835
Type species
†Esox lewesiensis
Mantell, 1822
Species

~26+, see text

Synonyms
  • Isodus Heckel, 1849
  • Phasganodus Leidy, 1857
  • Ischyrocephalus von der Marck, 1858
  • Solenodon Kramberger, 1881 (preocc.)
  • ?Tetheodus Cope, 1874
  • Holcodon Kramberger, 1885
  • Eurygnathus Davis, 1887 (preocc.)

Enchodus (from Greek: ἔγχος enchos, 'spear' and Greek: ὀδούς odoús 'tooth') is an extinct genus of aulopiform ray-finned fish related to lancetfish and lizardfish. Species of Enchodus flourished during the Late Cretaceous, where they were a widespread component of marine ecosystems worldwide, and there is some evidence that they may have survived to the Paleocene or Eocene; however, this may just represent reworked Cretaceous material.

Description

Enchodus species were small to medium in size, with E. zinensis reaching 172.2 centimetres (67.8 in) long. 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.

E. petrosus, with standard length around 76.7 centimetres (30.2 in) and sometimes over 1 metre (3 ft 3 in), is known from common remains coming 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, giving its skull an appearance somewhat reminiscent of modern deep-sea fishes, such as anglerfish and viperfish. Other species, such as E. parvus, were considerably smaller, measuring only some centimetres (a few inches) long.

Although Enchodus remains are among the most common Late Cretaceous bony fish fossils known worldwide, articulated specimens are relatively rare in North America, where the largest species are known from. The most complete Enchodus specimen from North America is the skeleton of an E. petrosus from the Pierre Shale of Wyoming & South Dakota, US. Other relatively complete or articulated skulls of are known of E. ferox from the Ripley Formation of Alabama and E. petrosus from the Austin Chalk of Texas. In 2026, the largest articulated Enchodus skull was described from an E. petrosus from the Bearpaw Formation of Alberta. The individual this skull belonged has been estimated as reaching 1.5 metres (4 ft 11 in) in total length.

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.[citation needed]

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 Mexico, South America (Tiupampan Santa Lucía Formation and Maastrichtian El Molino Formation of Bolivia, Paraíba, Pernambuco and Sergipe states of Brazil, as well as Argentina, Chile, and Peru), Africa (Egypt, Morocco, the Congo, Angola, Niger, and Equatorial Guinea), the Middle East (Saudi Arabia, Lebanon, Israel, Palestine and Jordan), Europe (England, France, the Netherlands, Belgium, Spain, Italy, Germany, Sweden, the Czech Republic, Slovenia, Greece, Ukraine and Russia), India, and Japan. Potentially the latest Enchodus remains are known from the earliest Eocene of Barmer, India. However, it has also been suggested that all post-Cretaceous Enchodus records are just reworked material.

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. The earliest known species is E. zimapanensis from the late Albian-aged El Doctor Formation of Mexico. Potentially earlier remains are known from the late Barremian/early Aptian of Brazil (Morro de Chaves Formation), but these specimens are too fragmentary to confidently assign to this genus.

Species

Specimen of E. gracilis
Reconstructed school of E. petrosus
Specimen of E. faujasi

Enchodus was a diverse, long-lived genus with many species known throughout its temporal and geographic range. The following valid species are known:

An undescribed species, previously tentatively assigned to the dubious species E. dirus, is known from the Maastrichtian of Gavdos, Greece. An indeterminate species, also previously assigned to E. dirus, is known from the Severn Formation of Maryland, US.

Many other dubious species based on insufficient remains have been described throughout its range. Even most of the valid Enchodus species are based on only isolated teeth and bones. For example, in 2026 the long-recognized species E. dirus (Leidy, 1857) was identified as a nomen dubium described from non-diagnostic remains. The genus Parenchodus, considered to be the sister genus of Enchodus, has been synonymized with this genus based on some studies. However, more recent studies have found it to be a valid genus distinct from Enchodus.

Phylogeny

Enchodus
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

References

  1. 1 2 3 Geology, British Museum (Natural History) Department of; Woodward, Arthur Smith (1901). Catalogue of the Fossil Fishes in the British Museum (Natural History): Actinopterygian Teleostomi of the suborders Isospondyli (in part), Ostariophysi, Apodes, Percesoces, Hemibranchii, Acanthopterygii, and Anacanthini. order of the Trustees.
  2. ↑ Roberts, George (1839). An etymological and explanatory dictionary of the terms and language of geology. London: Longman, Orme, Brown, Green, & Longmans. p. 55. Retrieved 30 December 2021.
  3. ↑ Fielitz, Christopher; González-Rodríguez, Katia A. (2010). "A New Species of Enchodus (aulopiformes: Enchodontidae) from the Cretaceous (albian to Cenomanian) of Zimapán, Hidalgo, México". Journal of Vertebrate Paleontology. 30 (5): 1343–1351. Bibcode:2010JVPal..30.1343F. doi:10.1080/02724634.2010.501438. JSTOR 40864352. S2CID 84281080.
  4. 1 2 3 Rana, R. S.; Kumar, K.; Singh, H.; Rose, K. D. (2005). "Lower vertebrates from the Late Palaeocene–Earliest Eocene Akli Formation, Giral Lignite Mine, Barmer District, western India". Current Science. 89 (9): 1606–1613. JSTOR 24110948.
  5. 1 2 Davis, Matthew P.; Fielitz, Christopher (December 2010). "Estimating divergence times of lizardfishes and their allies (Euteleostei: Aulopiformes) and the timing of deep-sea adaptations". Molecular Phylogenetics and Evolution. 57 (3): 1194–1208. Bibcode:2010MolPE..57.1194D. doi:10.1016/j.ympev.2010.09.003. PMID 20854916.
  6. 1 2 Díaz-Cruz, Jesús Alberto; Alvarado-Ortega, Jesús; Ramírez-Sánchez, Marcia M.; Bernard, Emma Louise; Allington-Jones, Lu; Graham, Mark (November 2021). "Phylogenetic morphometrics, geometric morphometrics and the Mexican fossils to understand evolutionary trends of enchodontid fishes". Journal of South American Earth Sciences. 111 103492. Bibcode:2021JSAES.11103492D. doi:10.1016/j.jsames.2021.103492.
  7. ↑ Everhart, Mike (2013). "Enchodus sp. - The Sabre-Toothed Fish of the Cretaceous". Oceans of Kansas. Archived from the original on November 18, 2022.
  8. ↑ Chida, Mori; Brinkman, Donald B.; Murray, Alison M. (October 2023). "A large, new dercetid fish (Teleostei: Aulopiformes) from the Campanian Bearpaw Formation of Alberta, Canada". Cretaceous Research. 150 105579. Bibcode:2023CrRes.15005579C. doi:10.1016/j.cretres.2023.105579. S2CID 258803963.
  9. ↑ Everhart, M.J. (2017). Oceans of Kansas, Second Edition: A Natural History of the Western Interior Sea (Life of the Past). Indiana University Press. p. 117. ISBN 978-0-253-02632-3.
  10. ↑ Goody, P. C.; Goody, P. C. (1976-01-01). "Enchodus (Teleostei: Enchodontidae) from the Upper Creatceous Pierre Shale of Wyoming and South Dakota with an evaluation of the North American enchodontid species". Palaeontographica, A Paläozoologie, Stratigraphie. 152 (4–6): 91–112. ISSN 0375-0442.
  11. ↑ Schein, Jason P.; Parris, David C.; Poole, Jason C.; Lacovara, Kenneth J. (2013). "A Nearly Complete Skull of Enchodus ferox (Actinopterygii, Aulopiformes) from the Upper Cretaceous Ripley Formation of Lowndes County, Alabama" (PDF). Contributions to Alabama Cretaceous Paleontology. 1: 78–83.
  12. ↑ Willimon, Edward L. (1973). "An Enchodontid Skull from the Austin Chalk (Upper Cretaceous) of Dallas, Texas". The Southwestern Naturalist. 18 (2): 201–210. doi:10.2307/3670420. ISSN 0038-4909.
  13. ↑ Nelson, Luke E.; Murray, Alison M.; Brinkman, Donald B. "Description of large, well-preserved Enchodus specimens from the Bearpaw Formation of Alberta, Canada". The Anatomical Record. n/a (n/a). doi:10.1002/ar.70248. ISSN 1932-8494.
  14. 1 2 Gouiric Cavalli, Soledad; Cione, Alberto Luis; Tineo, David; Pérez, Leandro Martín; Iribarne, Martín; Allcca Torres, Miguel A.; Poire, Daniel Gustavo (2020). "The first Peruvian record of Enchodus (Osteichthyes, Aulopiformes, Enchodontidae) in the Upper Cretaceous Vivian Formation". Andean Geology. doi:10.5027/andgeoV48n2-3337. ISSN 0718-7092.
  15. ↑ Kovalchuk, Oleksandr; Barkaszi, Zoltán; Anfimova, Galina (2022-03-31). "Records of Enchodus (Teleostei, Aulopiformes) from the Cenomanian of Ukraine in the light of European distribution of enchodontid fishes". Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen: 295–307. doi:10.1127/njgpa/2022/1049.
  16. 1 2 "PBDB Taxon". paleobiodb.org. Retrieved 2024-12-26.
  17. 1 2 3 4 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.
  18. 1 2 Fielitz, Christopher; GonzáLez-RodríGuez, Katia A. (2010). "A new species of Enchodus (Aulopiformes: Enchodontidae) from the Cretaceous (Albian to Cenomanian) of Zimapán, Hidalgo, México". Journal of Vertebrate Paleontology. 30 (5): 1343–1351. Bibcode:2010JVPal..30.1343F. doi:10.1080/02724634.2010.501438. ISSN 0272-4634.
  19. 1 2 3 4 Silva, Hilda M. A.; Gallo, Valéria (2011). "Taxonomic review and phylogenetic analysis of Enchodontoidei (Teleostei: Aulopiformes)". Anais da Academia Brasileira de Ciências. 83: 483–511. doi:10.1590/S0001-37652011000200010. ISSN 0001-3765.
  20. ↑ Díaz-Cruz, Jesús Alberto; Alvarado-Ortega, Jesús; Giles, Sam (2020-06-21). "A long snout enchodontid fish (Aulopiformes: Enchodontidae) from the Early Cretaceous deposits at the El Chango quarry, Chiapas, southeastern Mexico: A multi-approach study". Palaeontologia Electronica. Retrieved 2024-12-27.
  21. ↑ Enchodus at Fossilworks.org
  22. ↑ Friedman, M. (2012-01-01). "Ray-finned fishes (Osteichthyes, Actinopterygii) from the type Maastrichtian, the Netherlands and Belgium". Scripta Geologica. Special Issue. 08: 113–142. ISSN 0922-4564.
  23. ↑ Amalfitano, Jacopo; Giusberti, Luca; Fornaciari, Eliana; Carnevale, Giorgio (2020-04-03). "UPPER CENOMANIAN FISHES FROM THE BONARELLI LEVEL (OAE2) OF NORTHEASTERN ITALY". Rivista Italiana di Paleontologia e Stratigrafia. 126 (2). doi:10.13130/2039-4942/13224. ISSN 2039-4942.
  24. ↑ "Enchodus libycus". Mundo Fosil. Archived from the original on 2014-11-14. Retrieved 2015-05-13.
  25. 1 2 3 Nelson, Luke E.; Murray, Alison M.; Sims, Megan E. (2026-07-15). "A new species of Enchodus from the Western Interior Seaway of North America and a taxonomic revision of Enchodus dirus, Leidy, 1857". Journal of Vertebrate Paleontology. 0 (0) e2676733. doi:10.1080/02724634.2026.2676733. ISSN 0272-4634.
  26. 1 2 Cavin, Lionel; Alexopoulos, Apostolos; Piuz, André (2012-12-01). "Late Cretaceous (Maastrichtian) ray-finned fishes from the island of Gavdos, southern Greece, with comments on the evolutionary history of the aulopiform teleost Enchodus". Bulletin de la Société Géologique de France. 183 (6): 561–572. doi:10.2113/gssgfbull.183.6.561. ISSN 0037-9409.

Further reading