VALANGINIAN-LOWER HAUTERIVIAN BRACHIOPOD ASSEMBLAGES FROM THE KACHA-BODRAK INTERFLUVE, SOUTHWESTERN CRIMEA

Abstract

Brachiopods are among the fossils groups frequently occurring in sections of the southwestern Crimea. The analysis ofjoint stratigraphic distribution ofammonite and brachiopod assemblages that has been stimulated by revision of the Lower Cretaceous stratigraphy in that area (Baraboshkin, 1997a) shows that brachiopods are suitable for the correct age determination of their host rocks. The following brachiopod zones and beds are discriminated in the Valanginian-lower Hauterivian of the Crimean Mountains: Loriolithyris carteroniana (lower Valanginian), Loriolithyris metaitensis (lower-upper Valanginian), Musculina sanctaecrucis (lower Hauterivian) with the lower Musculina globus and upper Symphythyris neocomiensis subzones, and the Cyclothris corallina neocomiensis Zone, the latter distinguishable in shallow-water carbonate (reefal) and terrigenous facies. Some of these units are also established in other regions of the world. The new brachiopod species Musculina nuciformis Smirnova sp. nov., M. nikischini Smirnova sp. nov., Terebrataliopsis semicircularis Smirnova sp. nov., and T compacta Smirnova sp. nov. are described.