Gastrochaenolites Bioerosion in the Kalyanpur Limestone (Pliocene) of Dwarka Area, Kathiawar, Gujarat

Well preserved flask shaped borings belonging to ichnogenus Gastrochaenolites Leymerie, (1842) are being reported from the Kalyanpur Limestone Member (Pliocene) of Dwarka Formation, Jamnagar district, Kathiawar Region, Gujarat. The ichnofauna consists of Gastrochaenolites ampullatus Kelly and Bromley, G. cluniformis Kelly and Bromley, G. lapidicus Kelly and Bromley, G. orbicularis Kelly and Bromley, G. ornatus Kelly and Bromley, G. torpedo Kelly and Bromley, G. turbinatus Kelly and Bromley, and Gastrochaenolites isp. Though individuals of groups other than bivalves are known to create Gastrochaenolites-like borings, these borings were evidently emplaced by bivalves alone, confirmed by the presence of bivalve casts in some of the specimens. This hardground suggests an intraformational break in deposition.