Panxiosteus is an extinct monospecific genus of placoderm arthrodire from the Middle Devonian: Givetian stage of Yunnan province, China.

Phylogeny

Panxiosteus is a member of Panxiosteidae. In the 2010 Carr & Hlavin phylogenetic study, Panxiosteidae was recognized as the sister taxon to the family Dunkleosteidae, which together comprised the superfamily Dunkleosteoidea (one of the three major clades of Eubrachythoraci).[1] The phylogeny of Panxiosteus within Panxiosteidae is shown in the cladogram below from the 2013 Zhu & Zhu study:[2]

Eubrachythoraci
Dunkleosteoidea
Pachyosteomorphi

However, the subsequent 2016 Zhu et al. study using a larger morphological dataset recovered Panxiosteidae well outside of Dunkleosteoidea, instead within Coccosteomorphi and then Coccosteoidea as the sister group of Coccosteidae, as shown in the cladogram below:[3]

Eubrachythoraci
Coccosteomorphi
Pachyosteomorphi

References

  1. ^ Carr, R.K.; Hlavin, W.J. (2010). "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)". Zoological Journal of the Linnean Society. 159 (1): 195–222. doi:10.1111/j.1096-3642.2009.00578.x.
  2. ^ 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.
  3. ^ 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.


Allikas: https://en.wikipedia.org/wiki/Panxiosteus
No tags for this post.