Upper Cambrian and lowest ordovician articulate brachiopods from the Arbuckle and Wichita Mountains, Oklahoma

Brachiopods assigned to eight genera and 15 species have been recovered from Upper Cambrian (Franconian and Trempealeauan Stages) and lowest Ordovician strata in the Arbuckle and Wichita Mountains of Oklahoma. Species of Ocnerorthis and Eoorthis occur in the Reagan Sandstone and Honey Creek Limestone of the Timbered Hills Group. Species of Billingsella appear in the Honey Creek and range upward into the overlying Fort Sill and Signal Mountain Limestones of the Arbuckle Group. Species of Cymbithyris, Finkelnburgia, Nanorthis, and Apheoorthis succeed each other upsection in the Signal Mountain Limestone. Five brachiopod zones and one subzone have been established that can be used to correlate the measured sections in the Arbuckle and Wichita Mountains, and to correlate with varying degrees of confidence from Oklahoma to similar brachiopod occurrences in other areas in the United States.