The sea pens (Pennatulacea) and blue coral (Helioporacea) continue to be assigned separate orders, whereas the current order Alcyonacea was historically represented by four orders: Alcyonacea, Gorgonacea, Stolonifera and Telestacea.
Octocorallia is considered to be monophyletic, meaning that all contained species are descended from a common ancestor, but the relationships between subdivisions are not well known.