Cordibia pumila gen. et sp. nov. (Aulophyllidae, Dibunophyllinae) from the Lower Bashkirian E1 Limestone of the Donets Basin, Ukraine is described. The term “protocolony” is formally defined as a growth form intermediate between the solitary and colonial. Protocolonies consist of protocorallites and verticils of non-reproductive offsets [i.e., the lost structures]. The early ontogeny of a protocorallite is compared to the blastogeny in the same species in order to establish characters in common during both processes and to document the usefulness of blastogeny for phylogenetic reconstructions. The short duration and abundance of the occurrence (Limestones E1 up acme, E11) of that species also makes it a good marker for the lowest Feninian (= Krasnopolyanian) strata in the Donets Basin.
