title: Hadrosteus
text: # Hadrosteus
  
  Hadrosteus is an extinct monospecific genus of large arthrodire placoderm from the Late Frasnian (Late Devonian) Kellwasserkalk facies of Bad Wildungen, Germany. 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.
  
  ## Etymology
  
  The type species Hadrosteus rapax means "Rapacious Strong-Bone".
  
  ## Phylogeny
  
  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:
  
  