Middle and Upper Jurassic Ostracods from Western Kachchh, Gujarat, India: Biostratigraphy and paleobiogeography

Abstract

This paper presents a study of the Middle and Upper Jurassic Ostracods from Western Kachchh, India. The first part discusses the biochronological importance of the Ostracod assemblages, while the second part reports the paleobiogeographical results.Benthic foraminiferal biozones are used to calibrate the biostratigraphical distribution of ostracod species and genera from sections in the Aalenian–Tithonian interval located in Western Kachchh (or Kutch) (Mundham Anticline, Jumara Dome, Jhurio Dome and Habo Dome) and on Pachchham Island (Khavda Nala), Gujarat, India. A total of 71 species are listed, including 32 previously published species and 38 species in open nomenclature, belonging to 23 genera. The ostracod assemblages indicate that faunal communication was first established during the Bathonian and Callovian (Middle Jurassic) and continued until the early Cretaceous. These faunal exchanges occurred between Laurasia (USA, Europe, Russia and Siberia) and the Indo-East African Province, extending along the Western Tethyan carbonate shelves (bordering West and East Gondwana) through to the Pacific Ocean margin of West Gondwana.