Science. 1973 Apr 13;180(4082):188-90. doi: 10.1126/science.180.4082.188.
Ammonoid cephalopods serve significantly as a basis for correlation of strata near the boundary between the Paleozoic and Mesozoic Erathems. This is a report of the diagnostically Late Permian (uppermost Paleozoic) ammonoid Cyclolobus walkeri (Diener, 1903) from the Zewan Formation 20 meters below the Permian-Triassic contact at the classic section in Guryul Ravine, Srinagar region, Kashmir.
菊石类头足类动物对古生代和中生代地层边界附近的地层对比具有重要意义。本文报道了来自斯利那加地区古里乌尔峡谷经典剖面的泽万组（位于二叠纪-三叠纪接触带以下 20 米处）的具有诊断意义的晚二叠世（最上部的古生代）菊石 Cyclolobus walkeri（Diener，1903）。
