A New Radiolarian Genus Alexialeks gen. nov. and New Species from the Early Permian of the South Urals, Russia

Analysis of the morphology of radiolarian skeletons from the Lower Permian of the South Urals made it possible to revise the taxonomic assignment of Helioentactinia uralica Kozur et Mostler, 1989 and two different morphotypes of Helioentactinia sp. and assign them to three species within the new genus Alexialeks gen. nov.: A. uralicus (Kozur et Mostler, 1989), A. alius sp. nov. and A. distinctus sp. nov. Three pathways are recognized in the evolution of Alexialeks gen. nov. in the Asselian, Sakmarian, Artinskian, and Kungurian (Early Permian). The diagnoses of the genus Multisphaera Nazarov et Afanasieva in Afanasieva, 2000, emend. nov. and subfamily Multisphaerinae Nazarov et Afanasieva in Afanasieva, 2000, emend. nov. are emended. The validity of the subfamily Multisphaerinae Nazarov et Afanasieva in Afanasieva, 2000, emend. nov. is confirmed. A hypothesis is proposed that a primary inner sphere with a rudimentary four-ray spicule and numerous rod-like spines may represent a transitional form of the internal skeleton framework from an n-ray spicule to a true microsphere.