North American Paleozoic Chitinozoa

Chitinozoans have received little study by American paleontologists but newly re- ported occurrences from Ordovician, Silurian, and Devonian strata in North America suggest that they may become important stratigraphic indices. A rapid reconnaissance of wells, outcrops, field notes, etc., has yielded eighteen geographic occurrences and leads us to believe that these microfossils are widely distributed and abundant in the Paleozoic. More than 500 specimens have been examined. Study of a complete Silurian-Devonian core sequence in White Co., 111., has shown chitinozoans occur in three separate zones and represent two faunules. The taxonomic position of the Chitinozoa is discussed, and it is concluded that these microfossils represent an extinct order of rhizopod protozoans. The common association of chitinozoans and glauconite in the Clear Creek chert suggests that these microorganisms lived in relatively shallow marine waters in a moderately anaerobic environment. All previously recorded genera are briefly described, and two new genera, Ampullachitina and Illichitina, are proposed. All known species are listed and eleven new species from Illinois are described and illustrated.