Conodont micropalaeontology of mid-Ordovician aged limestone clasts from Lower Old Red Sandstone conglomerates, Lanark and Strathmore basins, Midland Valley, Scotland

Abstract. Mid-Ordovician limestone clasts in the Lower Old Red Sandstone conglomerates of the Lanark and Strathmore basins of the Midland Valley, Scotland, were derived from a cryptic carbonate platform, now hidden beneath the Southern Uplands Allochthon. These have yielded 17 multi-element species of conodonts, which are systematically described herein and include the eponymous biozonal species Pygodus serra and Pygodus anserinus. The fauna represents an outer shelf-ocean margin biofacies, found only in Upper Ordovician conglomerates in the Southern Uplands and the Malopolska Terrane, Poland.