Palmatolepis gracilis expansa Zone and Bispathodus aculeatus aculeatus Zone conodonts from the Three Lick Bed at the type locality, Ohio Shale, Upper Devonian, eastern Kentucky

The pentapartite Three Lick Bed separates the Huron Shale Member of the Ohio Shale from the overlying Cleveland Shale Member, which are part of the Upper Devonian fine-grained marine siliciclastic strata in the Appalachian Basin. Numerous palmatolepid, polygnathid and bispathodid conodonts, as well as a pyritized micro-molluscan dominated benthic fauna, indicate that the Three Lick beds were deposited as a dysoxic to anoxic substrate in an offshore deep shelf to basinal setting. The lower light grey bed of the Three Lick Bed contains a diverse conodont fauna that includes Palmatolepis gracilis expansa Sandberg and Ziegler, 1979, indicative of the Palmatolepis gracilis expansa Zone, and the occurrence of Bisptahodus aculeatus anteposicornis (Scott, 1961) in the middle light grey bed of the Three Lick Bed indicates the start of the Bispathodus aculeatus aculeatus Zone.