Morphometric data on topotype assemblage of Miogypsina (Lepidosemicyclina) droogeri, foraminifera from Kachchh, Gujarat

Abstract

Miogypsina (Lepidosemicyclina) droogeri Zone occupies an important position in the Indian biochronostratigraphy since the reservoirs of the giant oil field of Bombay High pertain to this zone. A rich assemblage of the topotype material from Kachchh is morphometically analysed for the better understanding of the variation in the population and its relation with the closely related species. The mean value of V is recorded as 77.5 for 24 specimens of Miogypsina (Lepidosemicyclina) droogeri Mohan and Tewari. The detailed study of Miogypsinidae from the exposures in Kachchh and a continuously cored offshore well ED-D from Bombay Offshore has helped in the better understanding of the evolution of Lepidosemicyclina lineage from Miogypsina (Lepidosemicyclina) thecideaeformis Rutten to Miogypsina (Lepidosemicyclina) droogeri Mohan and Tewari through Miogypsina (Lepidosemicyclina) talukdari Raju and Singh.