Affiliation: | 1.School of Forestry and Environmental Studies, Yale University, 195 Prospect Street, New Haven, CT 06511, USA;2.Department of Palaeobotany, Swedish Museum of Natural History, Box 50007, SE-10405 Stockholm, Sweden;3.Department of Earth Sciences, Royal Holloway, University of London, Egham, Surrey TW20 0EX, UK |