A new possible bivalve burrow Oblongichnus solodukhoi from the late Kazanian (middle Permian) stratotype section in Russia

A burrow previously assigned to the ichnotaxon Palaeophycus insignis is redescribed, and a new ichnotaxon Olongichnus solodukhoi n. igen. n. isp is erected for this flattened, slightly curved, multi-oriented, smooth burrow that has a thick lining with internal and external very fine-grained mucuous layers. It shows subrectangular to oblong form in cross section. O. solodukhoi is collected from the lowermost part of the Member D (Seryi Kamen Member, Pechishchi Beds) of the late Kazanian (middle Permian) stratotype section (East European Platform). It occurs in yellowish grey dolostone formed within open shallow-marine environments. O. solodukhoi records combined feeding and dwelling behaviours of a suspension-feeding organism. It could be produced by burrowing organisms with a simple flattened morphology, such as flatworms or polychaetes; however, we favour elongate and ultra-elongate bivalves as the potential tracemakers of the reported burrows.