New data on the problematic mollusc Jinonicella from the early Silurian of east Siberia

Abstract

ABSTRACT Jinonicella kolebabai Pokorný, 1978, a small problematic “mollusc” of unknown origin is described from the early Silurian (early to mid Llandovery) of east Siberia. This is the first record of Jinonicella from Siberia. Previous Silurian records of Jinonicella were from the late Llandovery (Telychian) of North America and the Wenlock to Ludlow of Europe (Bohemia, Gotland and the Carnic Alps of Austria). Jinonicella shows a wide range of geographic and stratigraphic distribution. It was reported from three palaeocontinents and several smaller terranes. It also demonstrates adaptation to different environments from shallow to deep-water settings, and spans several climatic zones from equatorial to temperate belts. The wide distribution and adaptation to a broad range of environments allow Jinonicella to subsist for about 100 my, i.e., from the Middle Ordovician to the Late Devonian surviving through two major extinction events.