Article: Caradoc–Ashgill conodont faunas from Wales and the Welsh Borderland

Twenty-two multi-element conodont species are described from Caradoc-Ashgill (Ordovician) strata sampled throughout Wales and the Welsh Borderland. Plectodina bullhillensis, P. bergstroemi, and Prioniodus deani are described as new species. Strata from the Costonian to Soudleyan stages appear to lie within the tvaerensis conodont Biozone, with Longvillian to ?Onnian strata in the superbus Biozone, and Pusgillian to Hirnantian strata in the ordovicicus Biozone, although in no sections are the zonal boundaries sharply defined. Contrasts in Colour Alteration Index suggest that the Caradoc-Ashgill rocks of the Welsh trough have been subjected to much higher geothermal temperatures than those on the Welsh Borderland platform.