The type species
P. macropterus was first named as a species of
Elops by
Henri Marie Ducrotay de Blainville in 1818, it was placed into the newly named genus
Pachycormus by
Louis Agassiz in 1833. Fossils have been found in marine deposits from France, Germany and England.
Pachycormus has recently been considered monotypic, only containing
P. macropterus, with other species considered junior synonyms of the former, though this has subsequently been questioned.
Pachycormus has generally been considered
basal among Pachycormiformes, with a recent phylogeny finding it to be the second most basal pachycormiform after
Euthynotus. == Description ==