Microbiota from the Kushalgarh Formation, Delhi Supergroup, India

Abstract

Well-preserved and diverse microfossils are described for the first time from the Kushalgarh Formation of Ajabgarh Group around Baraud Village in Alwar District, Rajasthan. The assemblage comprises 10 genera and 17 species belonging to filamentous and coccoid blue-green algae, of which two genera and 10 species are new. The new forms are Myxococcoides compactus sp. nov., Palaeolyngbya distinctica sp. nov., P. elongata sp. nov., P. baraudensis sp. nov., Palaeoscytonema indica sp. nov., P. intermingle sp. nov., P. misrae sp. nov., Ghoshia bifurcata gen. et sp. nov., Primorivularia robusta sp. nov. and Vesicophycus problematieus gen. et sp. nov. Morphological features and the size range of taxa suggest procaryotic nature of the assemblage. Coccoid forms are aggregated in colonies and dominated by filamentous forms. Baraud assemblage contains hormogonia, heterocysts, and false branching and the most significant is the record of true branching showing Stigonematalean affinity. The composition of the microflora suggests that the rocks of the Delhi Supergroup are equivalent to Vindhyans. This is also supported by the radiometric dates.