This last feature is important, as it allows sunlight to penetrate to the reef surface where it is used for photosynthesis by algae and many types of microbes. D uring the past five years, I have conducted an extensive research project on the reef fauna of the Racine Formation. This project involved careful study and identification of over 10,000 specimens in MPM collections. A major result of the project was the tabulation of 191 fossil species. This represents the highest recorded diversity for any Silurian reef community in the world.
Constructors build the reef by forming a framework of hard parts.
Stropmatoporoids built hard, calcarious skeletons shaped like domes, and they reached sizes of three feet. Tabulate corals, another type of constructor, are an extinct group of colonial animals distantly related to modern corals. Tabulates in the reefs are generally less than two feet in size, and their colony shapes include domes and chain configurations. B inders are organisms with a sheet-like form that grow over loose sediment and skeletal remains and literally bind them together. Binders in the Silurian reefs include stromatoporoids, tabulate corals and bryozoans, a still- living type of colonial animal.