EARLY CRETACEOUS TRIGONIIDS OF THE CRIMEA

Abstract

This study is the first of a series of works on trigoniids (Class Bivalvia) from the Lower Cretaceous of the Crimea. It contains systematic descriptions of nine genera and 15 species and subspecies of trigoniids from the Berriasian, Valanginian, Hauterivian, and Albian of the southwestern and central Crimea. The morphology and microstructure of the shells of juvenile and young individuals of three species are discussed. The stratigraphic sections containing trigoniids are briefly described. Three species assemblages (Berriasian, Valanginian-Hauterivian, and Albian) are recognized.