Rhomphaiodon Explained

Rhomphaiodon is an extinct genus of prehistoric sharks in the order Synechodontiformes that has been found in Late Triassic and Early Jurassic deposits located in Europe.^[1] The type species R. minor was originally named as a species of Hybodus in 1837 by Louis Agassiz.^[2] A second species, R. nicolensis, was added when the genus was named in 1993.^[3]

Fossil distribution

Fossils of Rhomphaiodon have been found in:^[4]

Triassic

• Grès de Mortinsart Formation, Norian-Rhaetian Belgium (R. minor)^[5]
• Sables de Mortinsart Formation, Norian Belgium (R. minor)^[6]
• near Saint-Laurent-du-Var, Rhaetian France (R. minor)^{[7] [8]}
• Gres à Avicula contorta Formation, Rhaetian France (R. nicolensis)^[9]
• Apfelstädtgrundes, Rhaetian Germany (R. minor)^[10]
• Kössener Schichten Formation (Cochloceras suessi ammonoid zone), Rhaetian Germany (R. minor)^[11]
• Steinmergel Group, Norian Luxembourg (R. minor)^{[12] [13]}
• Magnesian Conglomerate, Rhaetian England (R. minor)^[14]
• Westbury Formation, Rhaetian England (R. minor)^{[15] [16] [17]}
• Microlestes Quarry, Frome, Rhaetian England (R. minor)^[18]
• Manor Farm Quarry, Gloucestershire, Rhaetian England (R. minor)
• Penarth Group, Rhaetian England (R. minor)
• Cribbs Causeway, Bristol, Rhaetian England (R. minor)
• Pullastra Sandstone, Rhaetian England (R. minor)^[19]

Jurassic

• Aubange, Fleche (Hildoceras bifrons zone), Toarcian Belgium (R. minor)^[20]
• Dudelange, Ginzebierg, Toarcian Luxembourg (R. minor)^[21]
• Windsor Hill, Buckinghamshire (Lias Group?), Pliensbachian England (R. minor)^[22]

Notes and References

1. G. Cuny and S. Risnes. 2005. The Enameloid Microstructure of the Teeth of Synechodontiform Sharks (Chondrichthyes: Neoselachii). PalArch 3(2):9-19
2. L. Agassiz. 1837. Recherches Sur Les Poissons Fossiles. Tome III (livr. 8-9). Imprimérie de Petitpierre, Neuchatel viii-72
3. C. J. Duffin. 1993. Late Triassic sharks teeth (Chondrichthyes, Elasmobranchii) from Saint-Nicolas-de-Port (north-east France). Belgian Geological Survey, Professional Paper, Elasmobranches et Stratigraphie 264(1993):7-32
4. Web site: Rhomphaiodon. Fossilworks. 17 December 2021.
5. C. J. Duffin and D. Delsate. 1993. The age of the Upper Triassic vertebrate fauna from Attert (Province of Luxembourg, Belgium). Belgian Geological Survey, Professional Paper, Elasmobranches et Stratigraphie 264(1993):33-44
6. C. J. Duffin, P. Coupatez, J. C. Lepage and G. Wouters. 1983. Rhaetian (Upper Triassic) marine faunas from "Le Golfe du Luxembourg" in Belgium (preliminary note). Bulletin de la Société Belge de Géologie 92(4):311-315
7. G. Corroy. 1934. Les poissons et les reptiles du Muschelkalk et du Rhetien de Basse-Provence. Bulletin de la Société geologique de France 3, serie 5(5-6):475-483
8. V. Fischer, H. Capetta, P. Vincent, G. Garcia, S. Goolaerts, J. E. Martin, D. Roggero and X. Valentin. 2014. Ichthyosaurs from the French Rhaetian indicate a severe turnover across the Triassic-Jurassic boundary. Naturwissenschaften 101:1027-1040
9. [Denise Sigogneau-Russell|D. Sigogneau-Russell]
10. R. Amthor. 1908. Das Bonebed im Rhät des Apfelstädtgrundes südöstlich von Gotha. Zeitschrift für Naturwissenschaften 80:91-96
11. H. Zapfe. 1976. Ein großer Ichthyosaurier aus den Kössener Schichten der Nordalpen. Annalen des Naturhistorischen Museums in Wien 80:239-250
12. G. Hahn, J. C. Lepage, and G. Wouters. 1984. Cynodontier-Zähne aus der Ober-Trias von Medernach, Grossherzogtum Luxemburg [Cynodontian teeth from the Upper Triassic of Medernach, Grand Duchy of Luxembourg]. Bulletin de la Société Belge de Géologie 93(4):357-373
13. [Pascal Godefroit|P. Godefroit]
14. W. Buckland. 1824. Reliquiæ Diluvianæ; or, Observations on the Organic Remains Contained in Caves, Fissures, and Diluvial Gravel, and on Other Geological Phenomena, Attesting the Action of an Universal Deluge. Second Edition. John Murray, London 1-30
15. D. M. Martill and A. Dawn. 1986. Fossil vertebrates from new exposures of the Westbury Formation (Upper Triassic) at Newark, Nottinghamshire. Mercian Geologist 10(2):127-133
16. C. J. Duffin. 1982. Teeth of a new selachian from the Upper Triassic of England. Neues Jahrbuch für Geologie und Paläontologie, Monatshefte 1982(3):156-166
17. P. Egerton. 1854. On some new genera and species of fossil fishes. The Annals and Magazine of Natural History, Second Series 13:433-436
18. [Richard Owen|R. Owen]
19. W. A. Macfadyen. 1970. Geological Highlights of the West Country. A Nature Conservancy Handbook 1-296
20. D. Delsate and P. Godefroit. 1995. Chondrichtyens du Toarcien inferieur d'Aubange (Lorraine belge). Belgian Geological Survey, Professional Paper, Elasmobranches et Stratigraphie 278(1994):23-43
21. D. Delsate. 2003. Une nouvelle faune des poissons et requins Toarciens du sud du Luxembourg (Dudelange) et de L'Allemange (Schömberg). Bulletin de l'Académie Lorrain des Sciences 42:13-49
22. W. Kühne. 1956. The Liassic therapsid Oligokyphus. British Museum (Natural History), London 1-149