New data on the localities, morphology and taxonomy of the trilobites of Illaenidae family of the Idavere Regional Stage (Sandbyan) of Leningrad Region

In the paper 14 localities of the trilobites of the Idavere Regional Stage (Sandbian Stage) of Leningrad region are described. The taxonomic composition and distribution of the trilobite fauna of this region is specified. On the basis of new findings of shields and their fragments Neoillaenus itferensis (Holm) stat. n. is considered as a valid species. Lectotype of Neoillaenus itferensis (Holm) stat. n., which is given the status of a valid species here, is designated. Stenopareia asatkini sp. nov. is described. The distribution of Illaenus (Ruteniaeillaenus) dubari Krylov. is specified. Five species — Chasmops itferensis (Schmidt), Asaphus (Postasaphus) itferensis (Schmidt), Neoillaenus itferensis (Holm) stat. n., Illaenus (Ruteniaeillaenus) dubari Krylov and Atractopyge pauli Mannil — were used to denote biostratigraphic subdivisions — layers with the faun