On the Dimorph Pair Lobosphinctes/Planisphinctes (Ammonoidea: Perisphinctidae) from the Uppermost Bajocian–Lowermost Bathonian of the Kuban River Basin (Northern Caucasus, Russia)

Abstract

Upper Bajocian–Lower Bathonian perisphinctids are studied based on new collections from the upper part of the Upper Djangura Subformation in the interfluve of the Kuban and Urup rivers (Karachay-Cherkessia). Lobosphinctes costulatosus (Buckman) and Planisphinctes tenuissimus (Siemiradzki) are redescribed, and P. pirkli Mitta, sp. nov. is described; shells of Lobosphinctes loczyi (Papp) are identified. These taxa, found ex situ, are confined to the Densicosta and Bomfordi Subzones of the Upper Bajocian Parkinsoni Zone. Lobosphinctes dzhissaensis Mitta, sp. nov. is described from the Lower Bathonian (Zigzag Zone, Beds with Oraniceras scythicum)