Hadrosteus is an extinct monospecific genus of large arthrodire placoderm from the Late Frasnian (Late Devonian) Kellwasserkalk facies of Bad Wildungen, Germany.[1] It had large, double-pronged inferognathals (lower jawbones), and serrated edges along its mandible, strongly suggesting that it was a fish-eating predator. The head had a triangular snout, and the trunkshield was short, but high, with a median dorsal plate that was broader than wide. The average skull length is about 16 centimeters.[1]

Hadrosteus
Temporal range: Late Devonian: Frasnian, 382.7–372.2 Ma
Artist's reconstruction
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Placodermi
Order: Arthrodira
Suborder: Brachythoraci
Clade: Eubrachythoraci
Clade: Pachyosteomorphi
Clade: Aspinothoracidi
Genus: Hadrosteus
Gross, 1932
Species
  • Hadrosteus rapax Gross, 1932 (type)

Etymology

edit

The type species Hadrosteus rapax means "Rapacious Strong-Bone".[1]

Phylogeny

edit

Hadrosteus 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 Hadrosteus:[2]

Eubrachythoraci 

References

edit
  1. ^ a b c Denison, Robert (1978). Placodermi Volume 2 of Handbook of Paleoichthyology'. Stuttgart New York: Gustav Fischer Verlag. pp. 89–90. ISBN 978-0-89574-027-4.
  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.