The specimen shown above is a coral colony from the species Foerstephyllum vacuum. It was collected from the Late Ordovician Drakes Formation in Kentucky, from a unit known as the Otter Creek Coral Bed. There are several coral species found in this unit, with Foerstephyllum being the most prominent.
Foerstephyllum is a member of a group of corals known as the Tabulata. The tabulate corals were a highly successful and diverse group that were found worldwide during the Paleozoic Era over a span of more than 200 million years. Like so many other groups, the tabulates went completely extinct at the end of the Permian Period 250 million years ago, when roughly 95% of marine invertebrate species went extinct.