Contribution to the stratigraphy and vertebrate fauna of Lower Jurassic Kota Formation, Pranhita-Godavari Valley, India

Abstract

Gondwana Sequence of the Pranhita-Godavari Valley represents a thick succession of sediments ranging in age from Early Permian to Early Cretaceous. The Mesozoic Gondwana sediments contain a number of vertebrate bearing zones which are important for correlation and for assigning age to different units. New data on the vertebrate fossils of Kota Formation help trace the evolutionary history of early Jurassic mammals and dinosaurs and palaeogeographic configuration. The status of Gangapur Formation, as a unit, overlying Kota Formation and underlying Chikiala Formation is elaborated. Its lithological identity is established in the Yamanpalli area. Measured lithostratigraphic column of the limestone zone of the Kota Formation is described with the lithological variations and fossil contents. The data is useful for the correlation of limestone members in delineating the Kota Formation along its strike. Analysis of the geochemical data and vertebrate fossil community of Mesozoic sediments with particular emphasis on the Kota Formation, provide overwhelming evidences for freshwater environment of deposition of the Kota Formation. The evolutionary status of vertebrate fauna consisting of early mammals, dinosaurs and pholidophorid fishes is described which supports the Jurassic age of the Kota Formation.