See text The Dercetidae are an extinct family of aulopiform ray-finned fish that are known from the Late Cretaceous to the early Paleocene (and possibly to the Eocene if Stratodus is a member).

Many genera evolved a very slender body plan with elongated jaws, closely converging on modern needlefish.

[2][6][7] Initially, due to their slender appearance, dercetids were classified with the spiny eels in the order Notacanthiformes, but this was only based on their superficially similar body plans.

[2] The following genera are known:[7] The genus Robertichthys was previously considered a dercetid, but more recent studies suggest that it was an aspidorhynchid, a member of an entirely different group of fish.

Only a single genus, Scandiadercetis from the Danian limestone of the Limhamns kalkbrott, Sweden, is known from the Cenozoic, shortly after the extinction event.