The morphology and mode of formation of Neoeione igen. nov. from the Carboniferous of northern England

Samples of the burrows studied herein, originally introduced as Eione moniliformis Tate, have been collected from the heterolithic sandstone and siltstone beds of a coastal outcrop near the town of Howick, Northumberland United Kingdom. These interbedded and hummocky cross stratified beds, belonging to the Stainmore Formation, are Carboniferous and represent offshore marine sediment deposited between fair wave base and storm wave base. As the name Eione was used previously to describe a genus of gastropod, Eione Tate is a junior homonym of Eione Rafinesque. Therefore, a new ichnogenus was established, Parataenidium Buckman, to accommodate burrows composed of two distinct levels, which included E. moniliformis. Using three-dimensional morphological modeling techniques, this study aims to: 1) clarify the current taxonomic status of Parataenidium moniliformis; and 2) provide an updated model for its construction. The transfer of Eione moniliformis to Parataenidium was problematic; primarily because it is not composed of two distinct levels but instead composed of backfilled reniform sediment packages. These packages were created through a multistage process whereby the organism maintained a small open cavity from which it fed. Accordingly a new ichnogenus, Neoeione, is proposed to accommodate the material originally described by Tate.