A superfamily of comparatively large to small neogastropods. All species are scavengers or predators, occurring from tidal environments to great depths. Being mainly tropical in distribution, some species occur in northern Pacific temperate waters.
The Olivoidea are nowadays considered to contain two families, the Olividae and the Olivellidae. The differences between the two ar summarised below:
No or partial dissolution of early volutions of the shell. Filament channel either open, partly open, or closed.
Rhachidian tooth of radula tricuspidate or a modification of that type (with additional smaller flanking or in-between cusps)
Dissolution of early volutions of the shell. Filament channel always open.
Rhachidian tooth of radula multicuspidate.
Drez (1999), in a short but rather interesting paper, attempted to reconstruct the Olividae/Olivellidae phylogeny. At present, the molecular phylogeny is investigated in a project by Dr. Yu. Kantor, Dr. Ph. Bouchet, and others.
The Olividae seem to originate in the Maastrichtian (Upper Cretaceous) whereas the earliest occurrence of the Olivellidae is still unclear.