A well-preserved radiolarian assemblage was recovered from the Upper Jurassic section near the Rybaki village, Moscow Region, Central Russia. The radiolarians were found within the Amoeboceras serratum ammonite zone (upper Oxfordian), in phosphatized body chambers of ammonite shells. The radiolarian assemblage is represented by 23 species of 11 genera and displays Boreal affinity. It is characterized by abundance of Praeparvicingula: P. blackhorsensis (Pessagno and Whalen), P. donnae Bragin, P. elementaria (Carter), P. enormis (Yang) and by presence of the characteristic boreal family Echinocampidae (genera Echinocampe and Nordvikella). Five new species are described.
Radiolaria, Ammonites, Biostratigraphy, Jurassic, Oxfordian, Russia