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

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 <i>Glossopteris</i>, <i>Gangamopteris</i>, <i>Vertebraria</i>, <i>Noeggerathiopsis</i>, <i>Euryphyllum</i>, and scale leaf genera (<i>Glossotheca</i>, <i>Partha</i>, <i>Venustostrobus</i>, <i>Eretmonia</i>), reveals a highly diverse ecosystem of large trees and subcanopy shrubs. Leaf morphometry and venation patterns indicate significant evolutionary adaptations in <i>Glossopteris</i> 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 Paraná (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.