Erromenosteus is a genus of extinct, medium-sized brachythoracid arthrodire placoderm from the Late Frasnian of the Kellwasserkalk facies of Late Devonian Bad Wildungen and Bicken, Germany.
The various species had bullet-shaped heads, and curved, crushing jaws.
As was mentioned, all known species are from the German Kellwasserkalk facies.
[1]: 94 Now, though, Erromenosteus is considered a basal member of Dinichthyloidea.
These species were originally classified within Leiosteus before the genus was synonymized with Erromenosteus.