Otoceras Bed of Himalaya and Permian-Triassic Boundary-Assessment and Elucidation With Conodont Data

The history of research on the chronostratigraphic status of Otoceros fauna of Himalaya has been traced and the brachiopod, pelecypod and ammonoid biostratigraphy of the classical Otoceras bed of Himalayan sections has been critically reviewed. It is observed that the impact of over-all change in the palaeobiological communities, in the sense of change from Palaeozoic to Mesozoic, is better discernible at the base of Ophiceras bed. This megafaunal observation is supported from the vertical distribution of conodonts. This calls for revision of the traditional view of placing the Permian-Triassic boundary at the base of Otocerus bed.