Permian fossil whispers of ancient climates and forests: a megafloral-palynofacies odyssey in a part of eastern India

Abstract

The East Bokaro Coalfield offers significant insights into the palaeovegetation, palaeoclimatic conditions, and depositional environments prevailing during the late Artinskian-Kungurian age, corresponding to the deposition of Barakar sediments within the Gondwana Supergroup. A comprehensive analysis of megafloral assemblages, including Glossopteris, Gangamopteris, Vertebraria, Noeggerathiopsis, Euryphyllum, and scale leaf genera (Glossotheca, Partha, Venustostrobus, Eretmonia), reveals a highly diverse ecosystem of large trees and subcanopy shrubs. Leaf morphometry and venation patterns indicate significant evolutionary adaptations in Glossopteris flora, reflecting responses to climatic shifts. The warm-temperate climate, characterised by abundant water and sunlight, supported diverse vegetation and sustained the coal-forming flora. Palynofacies analysis identified two assemblages: PF-A, with opaque phytoclasts indicating oxidised, low-energy conditions, and PF-B, dominated by degraded organic matter and sub-dominant charcoal, reflecting suboxic-oxic conditions and periodic inundation. These findings suggest deposition in forest swamps, lake margins, and palaeomires under warm-temperate to humid conditions during the Kungurian, transitioning from cooler Artinskian climates. Comparative biostratigraphy with other Gondwana basins, including Karoo (South Africa) and Paran & aacute; (South America), highlights the ecological dominance of Glossopteridales and interconnectedness of Gondwanan ecosystems. Low-energy depositional settings suggest allochthonous sediment inputs. This study highlights the palaeobotanical and climatic dynamics of Gondwana during the Permian.