Ichthyodectiformes

Ichthyodectiformes is an extinct order of marine stem-teleost ray-finned fish. The order is named after the genus Ichthyodectes, established by Edward Drinker Cope in 1870. Ichthyodectiforms are usually considered to be some of the closest relatives of the teleost crown group.^[1]

Ichthyodectiformes Temporal range: Middle Jurassic-Early Paleocene PreꞒ Ꞓ O S D C P T J K Pg N
Xiphactinus audax Ichthyodectes ctenodon Cladocyclus gardneri Chirocentrites sp.
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Division:	Teleostei
Order:	†Ichthyodectiformes Bardack & Sprinkle, 1969
Subgroups
See text

They were most diverse throughout the Cretaceous period, though basal forms like Thrissops, Occithrissops and Allothrissops are known from the Middle-Late Jurassic of Europe and North America. They were almost entirely wiped out by the Cretaceous-Paleogene extinction event, but a single species, Saurocephalus lanciformis, appears to have survived into the earliest Paleocene (Danian).^[2]

Most ichthyodectiforms ranged between 1 and 5 meters (3–15 ft) in length. Most of known taxa were predators, feeding on smaller fish; in several cases, larger ichthyodectiforms preyed on smaller members of the order. Some species had remarkably large teeth, though others, such as Gillicus arcuatus, had small ones and sucked in their prey. Heckelichthys preopercularis is a rare example of non-predatory ichthyodectiform, more likely to be microphagous, fed on small particles.^[3] There is evidence that at least one species, Xiphactinus audax, may have been endothermic ("warm-blooded").^[4] Another genus, Dugaldia, may have been able to laterally open its mouth extremely wide in a manner akin to the modern sarcastic fringehead.^[5]

Systematics

The basal phylogeny is badly resolved, leading to many ichthyodectiforms that are simply known to be rather primitive, but where nothing certain can be said about their precise relationships.

†Ichthyodectiformes^[1][6][7]

• †Africathrissops Taverne, 2010^[8]
• †Allothrissops Nybelin, 1964
• †Altamuraichthys Taverne, 2016^[9]
• †Antarctithrissops Arratia et al., 2004^[10]
• †Ascalabothrissops? Arratia, 2000^[11]
• †Capassoichthys Taverne, 2015^[9]
• †Carsothrissops d'Erasmo, 1946^[12]
• †Dugaldia Lees, 1990
• †Faugichthys Taverne & Chanet, 2000
• †Furloichthys Taverne & Capasso, 2018^[9]
• †Garganoichthys Taverne, 2009^[9]
• †Occithrissops Schaeffer & Patterson, 1984
• †Ogunichthys Alvarado-Ortega & Brito, 2009
• †Pachythrissops? Woodward, 1919
• †Prymnetes Cope, 1871^[13]
• †Thrissops Agassiz, 1843
• †Sultanuvaisia Nesov, 1981
• †Unamichthys Alvarado-Ortega, 2004
• †Verraesichthys Taverne, 2010
• †Chuhsiungichthyidae Yabumoto, 1994^[14]
  • †Chuhsiungichthys Lew, 1974
  • †Jinjuichthys Kim et al., 2014
  • †Mesoclupea Ping & Yen, 1933
• †Bardackichthyidae Hacker & Shimada, 2021^[7]
  • †Amakusaichthys Yabumoto et al., 2020
  • †Bardackichthys Hacker & Shimada, 2021
  • †Heckelichthys Taverne, 2008
• †Cladocyclidae Maisey, 1991
  • †Aidachar Nesov, 1981^[15]
  • †Chirocentrites Heckel, 1849
  • †Chiromystus Cope, 1885
  • †Cladocyclus Agassiz, 1841
  • †Cladocynodon de Mayrinck et al., 2023^[16]
  • †Eubiodectes Hay, 1903
• †Ichthyodectidae Crook, 1892
  • †Cooyoo Bartholomai & Less, 1987
  • †Ghrisichthys Cavin et al., 2013
  • †Ichthyodectes Cope, 1870
  • †Postredectes Kaddumi, 2009^[17]
  • †Xiphactinus Leidy, 1870
• †Saurodontidae Cope, 1870^[18][19]
  • †Gillicus Cope, 1875
  • †Gwawinapterus Arbour & Currie, 2011^[20]
  • †Prosaurodon Stewart, 1999
  • †Saurocephalus Harlan, 1824
  • †Saurodon Hay, 1830
  • †Vallecillichthys Blanco & Cavin, 2003

References

1. Nelson, Joseph S.; Grande, Terry C.; Wilson, Mark V. H. (2016). Fishes of the World (5th ed.). John Wiley & Sons. ISBN 9781118342336.
2. Boles, Zachary; Ullmann, Paul; Putnam, Ian; Ford, Mariele; Deckhut, Joseph (2024). "New vertebrate microfossils expand the chondrichthyan and actinopterygian fauna of the Maastrichtian–Danian Hornerstown Formation in New Jersey". Acta Palaeontologica Polonica. 69. doi:10.4202/app.01117.2023. ISSN 0567-7920.
3. Baños-Rodríguez, Rocio Elizabeth; González-Rodríguez, Katia Adriana; Wilson, Mark V. H.; González-Martínez, Jorge Alberto (2020-06-01). "A new species of Heckelichthys from the Muhi Quarry (Albian–Cenomanian) of central Mexico". Cretaceous Research. 110: 104415. Bibcode:2020CrRes.11004415B. doi:10.1016/j.cretres.2020.104415. ISSN 0195-6671. S2CID 213275574.
4. Ferrón, H. G. (2019). "Evidence of endothermy in the extinct macropredatory osteichthyan Xiphactinus audax (Teleostei, Ichthyodectiformes)". Journal of Vertebrate Paleontology. 39 (6): e1724123. Bibcode:2019JVPal..39E4123F. doi:10.1080/02724634.2019.1724123. hdl:1983/e6d12da6-4f25-46ce-bb14-74fd2beddd82. S2CID 216158318.
5. Cavin, Lionel; Berrell, Rodney W. (2019-01-02). "Revision of Dugaldia emmilta (Teleostei, Ichthyodectiformes) from the Toolebuc Formation, Albian of Australia, with comments on the jaw mechanics". Journal of Vertebrate Paleontology. 39 (1): e1576049. doi:10.1080/02724634.2019.1576049. ISSN 0272-4634.
6. Cavin, L.; Berrell, R. W. (2019). "Revision of Dugaldia emmilta (Teleostei, Ichthyodectiformes) from the Toolebuc Formation, Albian of Australia, with comments on the jaw mechanics". Journal of Vertebrate Paleontology. 39 (1): e1576049. Bibcode:2019JVPal..39E6049C. doi:10.1080/02724634.2019.1576049. S2CID 190880286.
7. Hacker, R. J.; Shimada, K. (2021). "A new ichthyodectiform fish (Actinopterygii: Teleostei) from the Arlington Member (mid-Cenomanian) of the Upper Cretaceous Woodbine Formation in Texas, USA". Cretaceous Research. 123: 104798. Bibcode:2021CrRes.12304798H. doi:10.1016/j.cretres.2021.104798. S2CID 233806833.
8. Taverne, L. (2010). "Les Ichthyodectidae (Teleostei, Ichthyodectiformes) des schistes bitumineux de TAptien (Crétacé inférieur) de Guinée Équatoriale et du Gabon" (PDF). Bulletin de l'Institut Royal des Sciences Naturelles de Belgique (in French). 80: 115–143.
9. Taverne, L.; Capasso, L. (2018). "Osteology and phylogenetic relationships of Furloichthys bonarellii gen. and sp. nov. (Teleostei, Ichthyodectidae), a tropical fish from the Upper Cretaceous of central Italy" (PDF). Geo-Eco-Trop. 42 (1): 75–88.
10. Arratia, G.; Scasso, R. A.; Kiessling, W. (2004). "Late Jurassic fishes from Longing Gap, Antarctic Peninsula". Journal of Vertebrate Paleontology. 24 (1): 41–55. Bibcode:2004JVPal..24...41A. doi:10.1671/1952-4. hdl:11336/91532. S2CID 85783766.
11. Arratia, G. (2000). "Remarkable teleostean fishes from the Late Jurassic of southern Germany and their phylogenetic relationships". Fossil Record. 3 (1): 137–179. doi:10.1002/mmng.20000030108.
12. Palci, Alessandro; Jurkovšek, Bogdan; Kolar-Jurkovšek, Tea; Caldwell, Michael W. (2008-01-01). "New palaeoenvironmental model for the Komen (Slovenia) Cenomanian (Upper Cretaceous) fossil lagerstätte". Cretaceous Research. 29: 316–328. doi:10.1016/j.cretres.2007.05.003.
13. Blanco-Piñón, A.; Alvarado-Ortega, J. (2007). "Review of Vallecillichthys multivertebratum (Teleostei: Ichthyodectiformes), a Late Cretaceous (early Turonian) "Bulldog fish" from northeastern Mexico" (PDF). Revista Mexicana de Ciencias Geológicas. 24 (3): 450–466.
14. Kim, H.; Chang, M.; Wu, F.; Kim, Y. (2014). "A new ichthyodectiform (Pisces, Teleostei) from the Lower Cretaceous of South Korea and its paleobiogeographic implication". Cretaceous Research. 47: 117–130. Bibcode:2014CrRes..47..117K. doi:10.1016/j.cretres.2013.11.007.
15. Cavin, L.; Boudad, L.; Tong, H.; Läng, E.; Tabouelle, J.; Vullo, R. (2015). "Taxonomic Composition and Trophic Structure of the Continental Bony Fish Assemblage from the Early Late Cretaceous of Southeastern Morocco". PLOS ONE. 10 (5): e0125786. Bibcode:2015PLoSO..1025786C. doi:10.1371/journal.pone.0125786. PMC 4446216. PMID 26018561.
16. de Mayrinck, D.; Ribeiro, A. C.; Assine, M. L.; Spigolon, A. L. D. (2023). "A New Genus and Species of †Cladocyclidae (Teleostei: †Ichthyodectiformes) from the Lower Cretaceous "Batateira Beds", Barbalha Formation, Araripe Basin: The First Vertebrate Record in a Still Poorly Explored Fossil Site". Diversity. 15 (3): 413. doi:10.3390/d15030413.
17. Kaddumi, Hani F. (2009). "Ichthyodectids of the late Maastrichtian sediments of the Muwaqqar Chalk Marl Formation of Harrana". Fossils of the Harrana Fauna and the Adjacent Areas. Amman: Eternal River Museum of Natural History. OCLC 709582892.
18. Cope, E. D. (1870). On the Saurodontidæ. Proceedings of the American Philosophical Society 11:529-538
19. Cope, E. D. (1873). On two new species of Saurodontidae. Proceedings of the Academy of Natural Sciences of Philadelphia 25:2-339
20. Vullo, R., Buffetaut, E. and Everhart, M.J. (2012). "Reappraisal of Gwawinapterus beardi from the Late Cretaceous of Canada: a saurodontid fish, not a pterosaur." Journal of Vertebrate Paleontology, 32(5): 1198-1201. doi:10.1080/02724634.2012.681078

External links

• Media related to Ichthyodectiformes at Wikimedia Commons
• Data related to Ichthyodectiformes at Wikispecies