Introduction to the Rugosa
Extinct "horn corals"
The Rugosa are an extinct group of corals that were abundant in Middle Ordovician to Late Permian seas. Solitary rugosans are often referred to as "horn corals" because of their characteristic shape; two Paleozoic rugose corals are shown at the top of this page. Some solitary rugosans reached nearly a meter in length. However, some species of rugose corals could form large colonies.
