Early cretaceous floral diversity and ecology in the pranhita-godavari Basin, east coast of India

Abstract

Abundant plant fossils have been recovered from the Early Cretaceous (Berriasian-Aptian) fluvial sediments of the Gangapur Formation, Pranhita-Godavari Basin, east coast of India. The flora consists of ferns and gymnosperms. The fern components in the collection include Cladophlebis, Coniopteris and Gleichenia. The gymnosperms are represented by Elatocladus, Harrisiophyllum, Pachypteris, Pagiophyllum, Pityospermum, Ptilophyllum, Taeniopteris, Taxites and Torreyites. Three floral assemblages have been identified based on the relative association of various floral elements. First assemblage is principally composed of Elatocladus, along with Torreyites, Taxites and Harrisiophyllum. Second assemblage includes Cladophlebis, Gleichenia, Pachypteris, Taeniopteris and Pityospermum. Third assemblage mainly constitutes Ptilophyllum along with Pagiophyllum. These three assemblages are intrpreted as representating three communities, occupying three subenvironments within the river floodplain. Away from the river channel is probably occupied by first assemblage, the riverbanks by second assemblage and the openland/lowland area was by the third assemblage. Analysis of flora from present and previous studies highlighted the conifer dominance, both in abundance and diversity. Comparison of this floral assemblage with other Early Cretaceous floras of India and adjoining Gondwanan continents showed that the flora is more closely comparable with the Satpura Basin and Western Australian foras than the other Early Cretaceous floras of India, Southern Australia and Antarctica. The total flora with well diverse foliages and spores belonging to bryophytes, pteridophytes and gymnosperms from the Early Cretaceous of the PG Basin suggests prevalence of warm and humid climatic conditions during the time of deposition.