Abstract
Non-marine diatoms occur in the Deccan Intertrappean beds (Upper Cretaceous) of Mohgaon-Kalan, Chhindwara District, Madhya Pradesh and Pisdura, Lameta Formation (Upper Cretaceous), Maharashtra, India. This represents the oldest record of non-marine diatoms yet reported and the oldest from the Indian subcontinent. The diatoms were recovered from thin sections of chert and dinosaur coprolites by random fracturing. Solitary forms are the most common but colonial filaments up to five cells were also observed. Based on the morphological characters, the diatoms are identified as Aulacoseira Thwaites. The Lower Cretaceous marine diatom genus Archepyrgus Gersonde and Harwood also resembles Aulacoseira in general morphological characters and it seems that Aulacoseira evolved from Archepyrgus and migrated to the non-marine realm. Des Diatomées non-marines ont été trouvées en Inde, dans le Crétacé supérieur, dans les bancs intra-trappéens du Deccan, à Mohgaon-Kalan (district de Chhindwara, Madhya Pradesh) ainsi que dans la Formation de Lameta, à Pisdura (district de Chandrapur). Ce sont les plus anciennes Diatomées non-marines jamais signalées. Elles ont été observées au microscope optique dans des lames minces de cherts ainsi qu’au MEB à la surface de fractures de coprolithes de Dinosaures. Les cellules isolées sont les plus fréquentes mais des filaments coloniaux de plus de 5 cellules ont également été rencontrés. En se fondant sur leurs caractères morphologiques ces Diatomées ont été rapportées au genre Aulacoseira Twaites. Les Diatomées marines d’âge crétacé inférieur du genre Archepyrgus Gersonde and Harwood sont morphologiquement proches des Aulacoseira et il est possible que les Aulacoseira soient issues des Archepyrgus lors de leur migration dans des environnements non-marins.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.