1. Palaeobotany and Palynology Laboratory, Department of Botany, Sidho-Kanho-Birsha University, Purulia, India
2. CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, P.R. China
3. School of Environment, Earth and Ecosystem Sciences, The Open University, Milton Keynes, UK
4. Centre of Advanced Study, Department of Botany, University of Calcutta, Kolkata, India