These two species are of minor economic importance, but they are reasonably well known among sport fishers. All hiodontiform fishes share the following synapomorphies. Hyomandibular bone double-headed.
Dermosphenotic bone triradiate.
Opercle bone an irregular parallelogram. Dorsal arm of post-temporal bone more than twice as long as ventral arm. Seven-rayed pelvic fin. Recent study also suggests that the lower and upper jaws in Eohiodon woodruffi appear to be intermediate between those of Eohiodon rosei and those of Hiodon . In Hiodon it is anteriorly only as deep as or even slightly shallower than it is posteriorly.