New findings of Decapoda (Crustacea) in the Callovian of the Ryazan region (Central European Russia)

The decapod crustaceans of Central European Russia have been the subject of studies since the nineteenth century, and the only species, Eryma quadriverrucatum Trautschold, 1866 (Erymidae), has been found in the Callovian to the Oxfordian of that region. The present paper discusses the new exceptional findings of Solenoceridae, Glypheidae, and Mecochiridae from the upper Callovian sites of the Ryazan Region. The previously reported presence of Archeosolenocera sp. is confirmed in detail; Glypheopsis aff. G. etalloni (Oppel, 1861) and Eumorphia sp. are noticed for the first time for this area. Modern identification of erymids is reported: Eryma aff. E. ventrosum (von Meyer, 1835), E. ornatum (Quenstedt, 1858), and Stenodactylina insignis (Oppel, 1862) are noted in addition to E. quadriverrucatum. These findings address the gaps in the fragmented knowledge about the decapod fauna of Central European Russia and exhibit a differentiation of the local Russian decapod assemblage from those of Western Europe. The decapod community of the Ryazan region is considered to be associated with soft substrates of upper sublittoral zone.