Eubrachythoraci Explained

Eubrachythoraci is an extinct clade of arthrodire placoderms within the suborder Brachythoraci, armored fish most diverse during the Devonian. Most are considered to be pelagic (open ocean) long-distance swimmers, leading to their widespread distribution beginning from at least the Middle Devonian period.

Phylogeny

Brachythoraci is divided into the large derived clade Eubrachythoraci and several basal groups: Buchanosteoidea, Homosteidae, and Holonematidae.^[1] (Although Holonematidae's membership in Brachythoraci is disputed.)^[2]

Eubrachythoraci is then further divided into the sub-clades Coccosteomorphi and Pachyosteomorphi, the latter of which can be further sub-divided into Aspinothoracidi and Dunkleosteoidea,^[3] as shown in the cladogram below:^[2]

Notes and References

1. You-An Zhu . Min Zhu . A redescription of Kiangyousteus yohii (Arthrodira: Eubrachythoraci) from the Middle Devonian of China, with remarks on the systematics of the Eubrachythoraci . . 169 . 4 . 798-819 . 2013 . 10.1111/zoj12089 .
2. 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 . . 176 . 4 . 806–834 . 10.1111/zoj.12356. 0024-4082 . free .
3. Carr . R.K. . Hlavin . W.J. . Two new species of Dunkleosteus Lehman, 1956, from the Ohio Shale Formation (USA, Famennian) and the Kettle Point Formation (Canada, Upper Devonian), and a cladistic analysis of the Eubrachythoraci (Placodermi, Arthrodira) . . 159 . 1 . 195-222 . 2010 . 10.1111/j.1096-3642.2009.00578.x . free .