A Rhuddanian (Silurian, lower llandovery) pelmatozoan fauna from south‐west Wales

Only two crinoid faunas of Rhuddanian or early Aeronian age have been described hitherto, both from North America. A Rhuddanian pelmatozoan fauna from Haverfordwest, Dyfed, south‐west Wales includes the cheirocrinid rhombiferan cystoid Homocystites ? sp., plus the following crinoid species: the calceocrinid disparids Calceocrinus turnbulli sp. nov. and Calceocrinus ? sp.; the dendrocrinid cladid Dendrocrinus ? gasworksensis sp. nov.; the patelliocrinid monobathrid Macrostylocrinus ? sp. indet.; columnals of the rhodocrinitid(?) diplobathrid Floricolumnus (col.) sp. cf. F. (col.) girvanensis Donovan and Clark; the rhodocrinitid diplobathrid Chaosocrinus ornatus sp. nov.; and two indeterminate crinoid species. At the familial level this fauna shows strong similarities with coeval, but more diverse, crinoid assemblages from North America, suggesting that endemism did not develop until later in the Silurian.