Distribution and Stratigraphic Potential of the Mesozoic Radiolarian Family Prunobrachidae

The distribution and stratigraphic potential of the family Prunobrachidae Pessagno are studied. The recent discovery of new locations of the Prunobrachidae representatives in the Northeast of Russia increases the correlation potential of this family. In the Pacific Province in the Northern Hemisphere, the northernmost location of the prunoid radiolarians, is in the Chaun Bay region at 69° N (in modern coordinates) and the southernmost location is the Shikotan Island (Lesser Kuril Ridge) at 43° N. The biostratigraphic subdivision as the layer with Prunobrachium articulatum was first traced in the sections of the Koryak Highlands, Kamchatka Peninsula, and Shikotan Island. The level with Prunobrachium articulatum can be traced from the Russian Platform through the Urals and Western Siberia to the Pacific Margin.