Geographical distribution and species diagnostics of the Carboniferous and Permian genus Gzheloceras (Cephalopoda: Nautiloidea)

Abstract

The article is devoted to an attempt to trace the ways of distribution of Late Paleozoic nautilids Gzheloceras Ruzhencev et Shimansky, 1954. The genus Gzheloceras Ruzhencev et Shimansky (Cephalopoda: Nautiloidea) includes a large number of species from Carboniferous and Permian sediments. Representatives of the genus Gzheloceras were distributed mainly in the northern hemisphere. They inhabited the warm epicontinental seas of the northern and north-western periphery of the Palaeo-Tethys. Species of the genus Gzheloceras differ from each other by insignificant differences in the position of the siphuncle, the details of the surface ornamentation, less often in the form of suture and the shape of the cross section of the whorls. The form of the conch and a transverse ornamentation indicate a nectobenthic lifestyle of the genus Gzheloceras. The centre of origin of the genus is the waters on the place of modern Kazakhstan. In the Serpukhovian or Early Bashkirian, representatives of the genus Gzheloceras, apparently, dispersed into the Urals. The genus Gzheloceras flourished in the Early Permian of the Urals.