The taphonomy of a trilobite fauna from an uppermost Katian echinoderm Lagerstätte in South West Wales

Summary: The uppermost Katian (Rawtheyan) Slade and Redhill Mudstone Formation, in the Llanddowror area of Carmarthenshire in South West Wales, contains an horizon yielding abundant, articulated crinoids, cystoids, mitrate ‘carpoids’, asteroids and ophiuroids. This echinoderm Lagerstätte also includes a rich trilobite fauna dominated by illaenids and is thus unlike any of the other trilobite faunas in the formation, as is the occurrence of several enrolled or partially enrolled specimens. The trilobites and echinoderms provide the same taphonomic signal – the rapid transport and burial of organisms, leading to their death. Transport occurred within sand‐grade sediment without causing disarticulation of skeletons of the animals that were alive immediately prior to the event