Heintzosteus

Heintzosteus is an extinct genus of placoderm arthrodire fish,

Within Arthrodira, Heintzosteus is considered a member of "Phylctaenii", a paraphyletic grouping within the clade Phlyctaenioidei, basal to the suborder Brachythoraci. Heintzosteus is most closely related to Arctolepis and Dicksonosteus.