The first Silurian chitinozoans from Severnaya Zemlya, Arctic Russia

Silurian chitinozoans have not previously been reported from the Arctic Russia. By comparison, in the northern part of East Siberia (e.g. the Noril’sk area), chitinozoans are abundant and have a relatively diverse species composition (9 genera, 20 species), throughout the Silurian (Zaslavskaya 1983; 1986). The provincial affinities of the Siberian chitinozoan fauna, however, remain uncertain due to their endemism. Here we report the first record of early Silurian chitinozoans from the Severnaya Zemlya Archipelago. The new material originates from a mudstone bed of the Sredny Formation, exposed along the Ushakov River on the October Revolution Island. The recorded chitinozoan assemblage is monospecific and is represented by Conochitina aff. emmastensis. Conochitina emmastensis is the index species for the C. emmastensis Biozone (early Telychian, Llandovery, Silurian) defined in Baltica (Nestor 2009). This biozone is an important correlative level with other areas on a global scale. The presence of Conochitina aff. emmastensis suggests the early to late Telychian age for the strata bearing them. This is in accordance with the previous biostratigraphic dating based on graptolites (Bogolepova et al. 2000) and conodonts (Männik et al. 2009).