Lockeia : The Bivalves Resting Trace Fossils from Early Jurassic to Bajocian Thaiat Member of Lathi Formation of the Jaisalmer Basin, Western Rajasthan, India

This study focuses on the descriptions of well preserved numerous Lockeia traces of bivalves from the Early Jurassic to Bajocian Thaiat Member of Lathi Formation, Jaisalmer Basin, Western Rajasthan, India. Here, both ichnospecies Lockeia siliquaria and Lockeia cunctator have been recorded from the yellowish brown fine grained rippled calcareous silty sandstone in Thaiat Section. The L. siliquaria trace fossils are small, elongated almond-shaped and oval-shaped oblong body structures with smooth surfaces, occurring as positive hyporelief and more or less tapering at both ends. The L. cunctator trace fossils are small, almond-shaped oblong bodies with smooth surface structures, occurring as positive hyporelief with linear and club-shaped arrangement. The ichnotaxon L. siliquaria represents those places where the bivalve stopped temporally for feeding, whereas the L. cunctator are interpreted as locomotion traces with a resting or pro­bing component of bivalves. Based on Lockeia trace fossil assemblages with associated fauna and trace fossils, we suggest shallow-marine environment for the upper part of the Thaiat Member of Lathi Formation.