NEW SPECIES OF COILED NAUTILOIDS FROM THE PENNSYLVANIAN OF THE DONETS BASIN, UKRAINE

Анотація

Two new species of coiled nautiloids, Gzheloceras poletaevi sp. nov. and Celox oliphanti sp. nov., are described from the Late Bashkirian and Early Moscovian of the Central Donets Basin, Ukraine. Gzheloceras poletaevi sp. nov. differs from Gzheloceras aisenvergi in absence of a longitudinal ridge on the ventolateral shoulder and more compressed whorl profile; Gzheloceras poletaevi differs from Gzheloceras striatum in absence of a spiral lateral ribs and less compressed whorl. Gzheloceras poletaevi is distinguished from Gzheloceras memorandum by more compressed whorl profile and thinly discoidal conch. Gzheloceras poletaevi differs from Gzheloceras pulcher in the absence of a thin transverse lateral ribs and longitudinal ridge on the ventolateral shoulder. Celox oliphanti sp. nov. differs from Celox erratica by delicate growth lines on the conch surface and more rapid whorl’s increase in width and height.