Paleoenvironmental and paleobiogeographical implications of the microfossil assemblage from the Late Cretaceous intertrappean beds of the Manawar area, District Dhar, Madhya Pradesh, Central India

Abstract

An assemblage of microfossils consisting of non-marine ostracods (Cypridopsis, Gomphocythere, Zonocypris, Eucypris, and Frambocythere), charophyte gyrogonites (Platychara), molluscs (Viviparus, Valvata, and Lymnaea), and fish remains (mainly Phareodus), is here reported from a new intertrappean locality near the town of Manawar, District Dhar, Madhya Pradesh, Central India. The biotic component recovered suggests a Late Cretaceous (Maastrichtian) age for the intertrappean deposit near Manawar. Paleoenvironmentally, the overall biotic assemblage recovered indicates the presence of a freshwater palustrine/lacustrine depositional system connected to a low energy stream/river. Paleobiogeographically, the known high diversity of ostracod genera, especially Eucypris, Cypridopsis, and Gomphocythere, hints at endemism within the Indian Subcontinent during the Late Cretaceous (Maastrichtian). However, the cosmopolitan distribution of the charophyte genus Platychara in the K-Pg interval across the globe (Africa, Europe, and America) and its absence in the Upper Cretaceous of China and Mongolia is quite intriguing.

Keywords:

• Biota
• Central India
• Late Cretaceous
• Maastrichtian
• paleobiogeography
• paleoenvironment

Acknowledgements

VVK would like to thankfully acknowledge the use of infra-structural facilities at Birbal Sahni Institute of Palaeosciences (BSIP) where this investigation was carried out. VVK also acknowledges funding support from BSIP in the form of In-house Project No. 3.10 (XIII Five Year Plan). Encouragement from Prof. Sunil Bajpai (Director, BSIP) to carry out the study and for the approval to publish this research work (BSIP/RDCC/66/2017-18) is also gratefully acknowledged. VVK would also like to thank Prof. Christopher R Scotese (Director, PALEOMAP Project, Illinois, USA) for granting permission(s) to re-use and re-draw illustration(s). Help from Dr. Subodh Mishra (FESEM facility, BSIP) is also thankfully acknowledged. The authors thank Dr. Gareth J. Dyke (Editor-in-Chief) for initial scrutiny of the manuscript. We also gratefully acknowledge Prof. Spencer G. Lucas (New Mexico Museum of Natural History, USA) and an anonymous reviewer for their critical and insightful remarks that helped us in improving the manuscript.