Rhachiosteus is an extinct monospecific genus of arthrodire placoderm from the Middle to Late Devonian of Germany. It is known only from a single specimen, which may be a larval or juvenile form, as the skull of said specimen is only 19 millimetres long.[1]
Rhachiosteus | |
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Artist's reconstruction of Rhachiosteus (with Trematosteus in the background) | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | †Placodermi |
Order: | †Arthrodira |
Suborder: | †Brachythoraci |
Clade: | †Eubrachythoraci |
Clade: | †Pachyosteomorphi |
Genus: | †Rhachiosteus Gross, 1938 |
Species | |
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Phylogeny
editRhachiosteus is a basal member of the clade Pachyosteomorphi, the sister taxon to Coccosteomorphi, which together are the two main sub-clades of Eubrachythoraci. The cladogram below shows the phylogeny of Rhachiosteus:[2]
Eubrachythoraci |
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References
edit- ^ Denison, Robert (1978). Placodermi Volume 2 of Handbook of Paleoichthyology. Stuttgart New York: Gustav Fischer Verlag. p. 128. ISBN 9780895740274.
- ^ 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.