Kiangyousteus

Kiangyousteus is an extinct monotypic genus of dunkleosteid from the Middle Devonian: Givetian aged Guanwu Formation in the Sichuan province of south-western China. The type species, Kiangyousteus yohii, was the first known arthrodire from Asia.^[1]

Kiangyousteus Temporal range: Middle Devonian: Givetian, 387.7–382.7 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Kiangyouosteus yohii fossil material
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	†Placodermi
Order:	†Arthrodira
Suborder:	†Brachythoraci
Family:	†Dunkleosteidae
Genus:	†Kiangyousteus Liu, 1955
Type species
Kiangyousteus yohii Liu, 1955

Known remains in white

Life Restoration

Etymology

Kiangyousteus is named after Jiangyou (formerly ‘Kiangyou’) district of Sichuan Province, the location where the fossils were found in 1953 by Professor S. H. Yoh of Peking University.^[1]

Phylogeny

Kiangyousteus belongs to the family Dunkleosteidae. The phylogeny of Kiangyousteus can be shown in the cladogram below:^[1]

Dunkleosteoidea	Westralichthys uwagedensis Protitanichthys rockportensis Panxiosteidae Panxiosteus ocullus Janiosteus timanicus Plourdosteus canadensis Dunkleosteidae Eastmanosteus calliaspis Xiangshuiosteus wui Eastmanosteus pustulosus Kiangyousteus yohii Golshanichthys asiatica Dunkleosteus amblyodoratus Dunkleosteus terrelli Dunkleosteus raveri

Alternatively, the subsequent 2016 Zhu et al. study using a larger morphological dataset recovered Panxiosteidae well outside of Dunkleosteoidea, leaving the status of Dunkleosteidae as a clade grouping separate from Dunkleosteoidea in doubt, as shown in the cladogram below:^[2]

Dunkleosteoidea	Eastmanosteus calliaspis Eastmanosteus pustulosus Kiangyousteus yohii Golshanichthys asiatica Westralichthys uwagedensis Dunkleosteus raveri Dunkleosteus terrelli Dunkleosteus amblyodoratus Heterostiidae Heterosteus ingens Yinosteus major

References

1. You-An Zhu; Min Zhu (2013). "A redescription of Kiangyousteus yohii (Arthrodira: Eubrachythoraci) from the Middle Devonian of China, with remarks on the systematics of the Eubrachythoraci". Zoological Journal of the Linnean Society. 169 (4): 798–819. doi: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". Zoological Journal of the Linnean Society. 176 (4): 806–834. doi:10.1111/zoj.12356. ISSN 0024-4082.