Microfossils from the Neoproterozoic Gangolihat Formation, Kumaun Lesser Himalaya: Their stratigraphic and evolutionary significance

A well-preserved microbial assemblage from the Gangolihat Dolomite, Kumaun Lesser Himalaya is described in the present paper. The present assemblage contains both filamentous (septate and non-septate) and coccoidal microfossils besides acritarchs and sponge spicules. The assemblage includes 23 species belonging to 12 genera. Siphonophycus typicum is the most common species in the entire assemblage. The assemblage shows an abundance of filaments over coccoids and acritarchs. The assemblage includes Siphonophycus septatum, Siphonophycus. typicum, Siphonophycus robustum, Siphonophycus capitaneum, Siphonophycus kestron and Siphonophycus punctatum, Gunflintia minuta, Gunflintia grandis, Gunflintia barghoornii, Oscillatoriopsis media, Oscillatoriopsis obtusa, Oscillatoriopsis cuboides, Oscillatoriopsis sp., Nostocomorpha, Chlorogloeaopsis contexta, Obruchevella parvissima, Sphaerophycus parvum, Myxococcoides minor, Leiosphaeridia crassa, Trachyhystrichosphaera vidalii, Trachyhystrichosphaera sp., Micrhystridium pallidum, Cymatiosphaera minuta and sponge spicules of monaxons and hexactinellid affinity. The assemblage suggests a Neoproterozoic age for Gangolihat Dolomite. (C) 2009 Elsevier Ltd. All rights reserved.