(ĭkˈthē-ə-sôrˌ) also ich·thy·o·sau·rus(ĭkˌthē-ə-sôrˈəs)
nounpl.ich·thy·o·saurs also ich·thy·o·sau·ri(-sôrˈīˌ)
Any of various extinct fishlike marine reptiles of the order Ichthyosauria of the Triassic Period to the Cretaceous Period, having a porpoiselike head and an elongated, toothed snout.