Drilling predation is considered to be one of the major drivers of evolution in marine ecosystems. While different types of predation on Foraminifera have been documented, quantitative assessments of drilling predation on benthic foraminifers are rare compared to studies on other marine invertebrate groups. Here, we report predatory drilling traces on foraminiferal assemblages from the coastal region of Chandipur, Odisha, India. In the studied samples, only 22 out of 1627 individuals were drilled. In addition, drill holes, one each in Nonionella decora and Triloculina sp., were identified only under the SEM and not included in the ecological analyses. Most drill holes resembled Oichnus simplex, Oichnus paraboloides, and Oichnus ovalis, and only three holes resembled Fossichnus solus. In addition, predation was strongly taxon specific; out of 14 species identified, drill holes were found in only three species: Ammonia beccari, Ammonia dentata, and Astrorotalia trispinosa. Most of these holes were located at the ultimate or the penultimate chambers, and sometimes a specimen had multiple holes; this multiple drilling behavior is characteristic of juvenile gastropod drillers. Study of hole morphology further suggests that the holes were made by juvenile gastropods, which drill smaller benthic foraminifers to extract cytoplasm from their prey. The (paleo)ecological implications of this reported low intensity of predation are discussed.

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