The new ichnospecies Teredolites solitarius and its taphonomy from the Cenozoic carbonate intervals of Kutch Basin, India

Teredinidae is a family of bivalves occupying a spatial range of brackish to open-marine benthic niches and a stratigraphic range from Jurassic to recent. The teredinid genus Kuphus occurs within the calcareous muddy stiffground to hardground as vertical to inclined calcareous tubes. The ichnogenera Teredolites and Apectoichnus encompass the borings generally produced by the teredinids/shipworms. In the Kutch Basin, solitary teredinid borings range from the Eocene to the Early Miocene. Each subvertical boring has a calcareous wall with growth annulations on its outer surface. These tubes do not display any homeomorphic exoskeletal character. Rather, they manifest the producer’s ethology of mechanical boring into the organic-rich stiffground to hardground substrates and sustenance through microbially mediated chemosymbiosis. A systematic ichnotaxonomy is presented here for the solitary ‘Kuphus tubes’ which are classified as a new ichnospecies: Teredolites solitarius. The taphonomic analysis of the borings is based on the size, shape, orientation, and composite secondary borings, which are used in ascertaining the depositional conditions and palaeoecology. Two distinct taphofacies, i.e. TS-A and TS-B, have been identified. The TS-A represents the in-situ vertical morphotype formed in a restricted intermittently brackish mud-dominated inner carbonate ramp setting. The TS-B represents the reworked borings redeposited along with other bioclasts in a storm-influenced lower to middle shoreface setting.