Apophyses, verticiles, and denticles in skeletons of Late Paleozoic radiolarians of the subfamily Entactiniinae

Abstract

Morphostructural analysis of secondary skeletal elements, such as apophyses on the main spines and verticiles on the secondary spines of certain Late Paleozoic radiolarians of the subfamily Entactiniinae allow their taxonomic rank to be raised to genus. The presence of denticles on the secondary spines is only evidence of particular species. Three skeleton morphotypes are established: primary morphotype A, verticillate morphotype B, and apophyseal morphotype C. A new species, Entactinia mariannae sp. nov., and two new genera, Apophysiacus gen. nov. with five species, A. ichikawai (Caridroit et De Wever, 1984), A. minuta (Feng, 2007), A. praepycnoclada (Nazarov et Ormiston, 1983), A. pycnoclada (Nazarov et Ormiston, 1985), and A. sakmaraensis (Kozur et Mostler, 1989), and Verticillides gen. nov. with three species, V. nazarovi nom. nov., V. nestellae sp. nov., and V. verticillatus sp. nov., are described.