Gorgonichthys

Gorgonichthys Temporal range: Late Devonian: Famennian, 371.1–359.3 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Reconstruction of Gorgonichthys clarki
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	†Placodermi
Order:	†Arthrodira
Suborder:	†Brachythoraci
Clade:	†Eubrachythoraci
Clade:	†Pachyosteomorphi
Clade:	†Aspinothoracidi
Genus:	†Gorgonichthys Claypole, 1892
Species
Gorgonichthys clarki Claypole, 1892 (type)

The infragnathals (lower jaws) of Gorgonicthys with a 1-liter water bottle for scale (bottle is approximately 23 cm tall). These specimens were collected from the Cleveland Shale and are in the collections of the Cleveland Museum of Natural History's Department of Vertebrate Paleontology.

Ventral plates of Gorgonichthys clarki

Gorgonichthys is extinct monospecific genus of large arthrodire placoderm. Fossils are found in the Upper Famennian Cleveland Shales of Late Devonian in Ohio. The type species is Gorgonichthys clarki.

Description

Gorgonichthys had sharp, pointed edges on the dental plates of the upper and lower jaws.[1] With a headshield length of up to 70 cm (28 in),[2] it is estimated to have been comparable to the size of Dunkleosteus.[3]

Phylogeny

Gorgonichthys is a member of the clade Aspinothoracidi, which belongs to the clade Pachyosteomorphi, one of the two major clades within Eubrachythoraci. It is closely related to the family Selenosteidae, and could possibly be included in that family. The cladogram below shows the phylogeny of Gorgonichthys:[4]

Eubrachythoraci

Coccosteomorphi  Pachyosteomorphi  Rhachiosteus pterygiatus Dunkleosteoidea  Eastmanosteus calliaspis Eastmanosteus pustulosus Kiangyousteus yohii Golshanichthys asiatica Westralichthys uwagedensis Dunkleosteus raveri Dunkleosteus terrelli Dunkleosteus amblyodoratus  Heterostiidae  Heterosteus ingens Yinosteus major Aspinothoracidi Tapinosteus heintzi Bullerichthys fascidens Kendrickichthys cavernosus Bruntonichthys multidens Dinichthys herzeri Hadrosteus rapax Gorgonichthys clarki  Selenosteidae  Heintzichthys gouldii Pachyosteus bulla Gymnotrachelus hydei Stenosteus angustopectus Brachyosteus dietrichi Melanosteus occitanus Rhinosteus parvulus

According to a 2022 Jobbins et al. study, Gorgonichthys was found to be more related to Heintzichthys than Gymnotrachelus, potentially making Gorgonichthys a member of Selenosteidae.[5]

	Gymnotrachelus Gorgonichthys Heintzichthys

References

1. Charlie Underwood, Martha Richter, Zerina Johanson (2019). Evolution and Development of Fishes. Cambridge University Press. p. 13. ISBN 9781107179448. Retrieved 1 September 2022.
2. John A. Long. "A new dinichthyid fish (Placodermi: Arthrodira) from the Upper Devonian of Western Australia, with a discussion of dinichthyid interrelationships". Rea. West. Aust. Mus. 1987, p. 537.
3. Joseph S. Nelson, Terry C. Grande, Mark V. H. Wilson (2016). Fishes of the World. Wiley. p. 40. ISBN 9781119220817. Retrieved 1 September 2022.
4. Zhu, You-An; Zhu, Min; Wang, Jun-Qing (1 April 2016). "Redescription of Yinostius major (Arthrodira: Heterostiidae) from the Lower Devonian of China, and the interrelationships of Brachythoraci". Zoological Journal of the Linnean Society. 176 (4): 806–834. doi:10.1111/zoj.12356. ISSN 0024-4082.
5. Jobbins, Melina; Rücklin, Martin; Ferrón, Humberto G.; Klug, Christian (2022). "A new selenosteid placoderm from the Late Devonian of the eastern Anti-Atlas (Morocco) with preserved body outline and its ecomorphology". Frontiers in Ecology and Evolution. 10. doi:10.3389/fevo.2022.969158. hdl:10550/85583. ISSN 2296-701X.