The trace fossil Asthenopodichnium lithuanicum isp. nov. from Late Neogene brown-coal deposits, Lithuania

Abstract

A new freshwater ichnospecies of Asthenopodichnium Thenius, A. lithuanicum, is distinguished by its pouch-like shape with a J-shaped limb that is distinctly wider than the remaining part of the pouch. It was produced in a stiffground at the top of a mineral-rich brown-coal layer of Neogene age by a suspension feeder forming pouch-like domichnial cavities. Mayfly larvae may perhaps be considered as candidates for its tracemaker. Other arthropods (amphipods, isopods) are also possibilities. The brown-coal layer was exposed during the Neogene by river erosion, was colonized by the tracemaker (locally two colonization events took place) and in the Pliocene covered by distal crevasse and river channel sands.