New Radiolaria Species from the Cenozoic Deposits on the Island Slope of the Kuril–Kamchatka Trench

Abstract

Descriptions of four new radiolarian species from the material collected from the Cenozoic deposits of the submarine Vityaz Ridge (the island slope of the Kuril–Kamchatka Trench) are provided in the article. The descriptions of the new species Amphistylus gladiusiacus sp. nov. and Thecosphaerella tochilinae sp. nov. from the Upper Eocene–Lower Oligocene deposits are based on the criteria established for the class of spherical porous Sphaerellaria: the number of skeletal shells, the shape of the cortical shell, and the development of the system of spines and axopodial complex. The new species Stylotrochus bipedius sp. nov. and S. tripedius sp. nov. from the Lower Pleistocene are considered among stauraxon radiolarians of the class Stauraxonaria due to the discoid geometric shape of their skeleton. The history of changes in the systematic position of the family Spongodiscidae is reviewed, and a proposal is made to restore the name of the order Discoidea Haeckel, 1862.