Calymenid trilobites from the Wenlock Series (Silurian) of Britain

Abstract

ABSTRACTMost species of calymenid trilobite from the Wenlock Series of Britain are revised. In total, British trilobites of this family and epoch comprise nine species and three genera, with a further six species being referred to under open nomenclature: Calymene is represented by five species, Tapinocalymene by three and Diacalymene by one. One new subspecies, C. neotuberculata ludicra, and one new species, C. fuliginata, from the lower and upper Wenlock, respectively, are established. The previously monotypic D. allportiana (Salter, 1865) is now known from about 50 specimens. The upper Wenlock Much Wenlock Limestone Formation yields five species, the most for any formation. Calymene occurs mostly in the shallower water facies on the western edge of the Midland Platform and eastern and southern margins of the Welsh Basin, Tapinocalymene essentially in the more offshore carbonate muds of this basin and D. allportiana on the fringe of the Midland Platform and more offshore carbonate muds. British Wenlock calymenids show some affinity with those of the Scandinavia-Baltic area. C. tuberculosa Dalman, 1827 is recorded with certainty in situ outside Gotland for the first time.