Dinichthys

Not to be confused with Dinictis.

Dinichthys Temporal range: Late Devonian: Famennian,
File:Dinichthys herzi.jpg
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	†Placodermi
Order:	†Arthrodira
Clade:	†Phlyctaenioidei
Suborder:	†Brachythoraci
Clade:	†Eubrachythoraci
Clade:	†Pachyosteomorphi
Clade:	†Aspinothoracidi
Genus:	†Dinichthys Newberry, 1868
Species
Dinichthys herzeri Newberry, 1868 (type)
Synonyms
Ponerichthys Miller, 1892

Dinichthys (from Greek: δεινός deinós, 'terrible' and Greek: ἰχθύς ichthys 'fish') is an extinct monospecific genus of large marine arthrodire placoderm from the Late Devonian (Famennian stage) measuring around 3 metres (9.8 ft) long. Fossils were recovered from the Ohio Shale Formation along the Olentangy River in Delaware County, Ohio.

Classification History

File:Dinichthys herzeri.jpg

Life restoration

Dinichthys was originally described in 1868 by John Newberry on the basis of an incomplete skull roof and mandibles (holotype AMNH 81). Subsequently, many unrelated large arthrodires were originally classified together within this genus, including species now assigned to Dunkleosteus, Eastmanosteus, and Titanichthys. Notably, the type species of Dunkleosteus was originally described as Dinichthys terrelli by Newberry in 1873, and was later separated into Dunkleosteus by Jean-Pierre Lehman in 1956. Dunkleosteus was still thought to be closely related to Dinichthys, and they were grouped together in the family Dinichthyidae. However, in the 2010 Carr & Hlavin phylogenetic study, Dunkleosteus and Dinichthys were found to belong to two separate clades. Carr & Hlavin resurrected the family Dunkleosteidae and placed Dunkleosteus, Eastmanosteus, and a few other genera from Dinichthyidae within it. Dinichthyidae, in turn, is left a monospecific family and dismissed as a family grouping, and the genus Dinichthys is now considered a monotypic genus, containing only the type species, D. herzeri.

Phylogeny

Dinichthys is a member of the clade Aspinothoracidi, which belongs to the clade Pachyosteomorphi, one of the two major clades within Eubrachythoraci. The cladogram below shows the phylogeny of Dinichthys:

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