Decay and Disarticulation of the Cockroach: Implications for Preservation of the Blattoids of Writhlington (Upper Carboniferous), UK

Abstract Cockroaches are the dominant insects in Carboniferous terrestrial biotas, however, approximately 90% of specimens consist only of isolated wings or wing fragments. This bias has been attributed variously to decay and selective preservation, transport, predation, or collection. The state of preservation of Carboniferous cockroaches was documented in extensive collections from the Westphalian at Writhlington, U.K., where collection bias was minimal. The wings may be intact, or more usually fracture across the veins. Laboratory experiments were conducted on the genera Periplaneta and Blaberus to determine the effects of decay and transport following drowning. The decay experiments revealed a series of disarticulation stages that were reached more rapidly in specimens transported in a circular flume, particularly where some decay had occurred first. The wings detached from the body at a late stage, and separated to varying degrees along the veins, whether or not transport was involved. Experiments on...