The muricid gastropod genus Ecphora Conrad, 1843, comprises Oligocene
to Pliocene species from eastern North America and Oligocene to Middle
Miocene species from Europe. Earlier workers speculated that it evolv
ed in North America from an Early Oligocene Tritonopsis-like ancestor.
Evidence from previously unstudied shell characters indicates that Ec
phora belongs to the subfamily Ocenebrinae, whereas Tritonopsis is a s
ubgenus of Cymia Morch, 1860, a member of the Rapaninae. Ecphora lacks
the parietal rib, lirate outer lip, and adapical extension of the out
er lip of Cymia and related genera, and may have been derived from an
as yet unknown ocenebrine ancestor in which the external shell sculptu
re was predominantly or exclusively spiral.