Chitinozoa from the middle Ordovician Bromide Formation, Arbuckle Mountains, Oklahoma, U.S.A.

Chitinozoans from the lower middle Ordovician of Oklahoma have good stratigraphic potential. They are close to faunas described from the Southern Appalachians, the Cincinnati Region and Baltoscandia, but less similar to those from eastern Canada, Great Britain and southwestern Europe. Sediments from relatively deep water contain more diverse and abundant assemblages than shallow water sediments. One species, Hercochitina bromidensis, is new.