Ptychoplasma and associated ichnotaxa of bivalve burrowing activity in Kuldhar Member of Jaisalmer Formation, Jaisalmer Basin, western India

This study records the four ichnotaxa of burrowing activity of bivalves ascribed to Ptychoplasma excelsum, Ptychoplasma vagans, Lockeia siliquaria, and Lockeia cunctator from the Kuldhar Member of the Jaisalmer Formation of the Jaisalmer Basin, western India. These trace fossils have been recovered from the exposed road-cut section on the Jaisalmer-Sam Road near Kuldhara village. Here, Ptychoplasma excelsum is the first report from the Jaisalmer Basin. The Ptychoplasma excelsum are discovered as epichnial convex discontinuous ridges that connect through welding of the host rock strata, whereas the Ptychoplasma vagans are almond-shaped bodies that appear erratically, are oriented serially, and form looping or meandering patterns. The Lockeia siliquaria are almond-shaped traces with a tapering end and are found in isolated forms, while Lockeia cunctator are almond-shaped traces that are found in serially connecting forms or club-shaped structures. These trace fossils represent the repichnia and cubichnia behaviours of the burrowing bivalves. This study implies the shallow-water depositional settings for the Kuldhar Member of the Jaisalmer Formation.