The Elements of Evolution (160-3) Reefs

Reefs

The impressive Devonian reefs were a concerted construction by calcareous algae, coral, bryozoans, and sponges, among others. After their devastation at the end-Devonian Hagenberg extinction event, the knack of communities forming to build robust burghs on the sea floor was lost for almost 100 million years. Only in the late Permian did reefs make a comeback, and their scale paled in comparison.