Both names, i. e. Hexacorallia and Zoantharia, and their English equivalents, also have narrower meanings - see below in the chapter Taxonomy. The name Hexacorallia also has a rare meaning unrelated t
Aspidiscus cristatus from the Cenomanian (Upper Cretaceous) of southern Israel; oral view.
Aspidiscus cristatus from the Cenomanian (Upper Cretaceous) of southern Israel; aboral view.
The Rugosa are an extinct class of solitary or colonial corals that were abundant in Middle Ordovician to Late Permian seas.
A close view of a Petoskey stone. Actually the colonial rugose coral Hexagonaria, a columnariine from Middle Devonian Michigan.
Three views of Grewingkia canadensis, a solitary streptelasmatine from Ordovician Indiana
Cyathophylloides sp., a colonial stauriine from the Late Ordovician, Georgian Bay Formation, Ontario, Canada