Dicoelitid belemnites from the Caucasian margin of the Tethys: new data from the Upper Bajocian-Lower Bathonian of Karachay-Cherkessia, southwest Russia

Abstract

Early representatives of the belemnite family Dicoelitidae (Belemnopseina) from the Northern Caucasus are reported from the Upper Member of the Djangura Formation of Karachay-Cherkessia. We document the first records of Dicoelites (s. str.) from the Upper Bajocian of Eastern Europe and introduce the new species Dicoelites aprilis Dzyuba sp. nov. and Dicoelites octobris Dzyuba sp. nov. Additionally, Conodicoelites sp. from the Upper Bajocian as well as a new record of Conodicoelites exiguus (Krimholz, 1953) from the Lower Bathonian are described. New belemnite records from Karachay-Cherkessia indicate the successive appearance of dicoelitid genera in the Caucasian margin of the Tethys during the Late Bajocian, i.e. Dicoelites in the late Niortense Chron and Conodicoelites in the early Garantiana Chron. Our data provide evidence supporting the presence of Dicoelites in the Bajocian deposits of the western Tethyan domain that was previously considered doubtful