Ichnofossils and their significance in the Cambrian successions of the Parahio Valley in the Spiti Basin, Tethys Himalaya, India

Ichnology of the Early Cambrian Tal Group, Mussoorie Syncline, Lesser Himalaya, India

“…Description: Series of isolated, slightly curved ridges repeated laterally, moderately spaced from each other; ridges vary in length from 8-10 mm, in width from 1.5-2 mm and are 2-3 mm apart from each other. Remarks: The present specimen differs from Monomorphichnus monolinearis described from Kashmir by Shah and Sudan (1983) and with the species of Monomorphichnus described from Zanskar (Parcha 1998;Parcha and Singh 2010) and Spiti (Parcha and Pandey 2011) in the nature and pattern of the ridges. The present specimens equally differ from Monomorphichnus species described from member A of the Dhaulagiri Formation of the Lesser Himalaya (Tiwari and Parcha 2006), Monomorphicnus lineatus described from Calcareous member of Deo-ka-Tibba and A, B members of Dhaulagiri Formation in Nigalidhar Synform (Desai et al 2010) and from Monomorphichnus isp.…”

“…Remarks: The present specimen is grouped under the ichnogenus Diplichnites because of the presence of serial markings and curved nature. The specimen differs with Diplichnites ichnospecies described from the Lesser, Spiti and Zanskar Himalaya in the absence of two parallel, equally spaced rows (Parcha 1998;Tiwari and Parcha 2006;Parcha and Singh 2010;Parcha and Pandey 2011).…”

“…Remarks: The present specimen shows close similarity with the ichnogenus Palaeopasichnus in nature and pattern of bars. The specimen differs from Palaeopasichnus from the Cambrian of Spiti Basin in its unbranching nature (Parcha and Pandey 2011).…”

“…The specimen differs from Dimorphichnus isp. reported from the Cambrian sequences of the Tethyan Himalayan region, in nature and pattern of wedge markings (Shah and Sudan 1983;Bhargava and Bassi 1988;Parcha 1998;Parcha and Singh 2010;Parcha and Pandey 2011). It equally differs from the ichnospecies Dimorphichnus described by Singh and Rai (1983) and by Tiwari and Parcha (2006) from the Lesser Himalaya and also with the species described by Kumar and Pandey (2010) from Rajasthan.…”

“…The present form differs from the Nereites isp. described from the Spiti Basin in having a single row of claw markings as compared to two rows in the latter (Parcha and Pandey 2011).…”