A Lower Pennsylvanian (Morrowan) silicified ostracode fauna occurs just above the conformable Mississippian-Pennsylvanian boundary within the Barnett Formation in Texas. The fauna contains several taxa that were previously restricted to the Upper Mississippian and numerous taxa only known from the Lower Pennsylvanian. New taxa proposed include Amphissites (Amphissites) morrowanensis n. sp., Polytylites subrectus n. sp., Kirkbyella (Berdanella) delicata n. sp., Kindlella proscillata n. sp., Libumella walkerorum n. sp., Moorites tumidus n. sp., Leptoderos arytaina n. gen. and sp., and Cribroconcha prolixa n. sp.