Chitinozoan Faunule of the Devonian Cedar Valley Formation

The chitinozoan faunule of the upper Middle Devonian Cedar Valley formation from a single outcrop in northwestern Illinois is described. The faunule, which is abundant and diversified, represents more than thirteen species referable to four genera. One new genus, Earlachitina, and eight new species are described and named.

The faunule is distinct from the previously described Devonian Clear Creek, Bailey, and Grand Tower faunules of Illinois and Indiana, but has elements in common with Devonian faunules from Brazil and Germany.

The technique of collecting and preparing chitinozoan specimens from limestone is discussed.