1. Department of Palaeobotany; Swedish Museum of Natural History; Svante Arrhenius Väg 7 SE 10405 Stockholm Sweden
2. Department of Ecology and Evolutionary Biology; Biodiversity Institute; University of Kansas; 1200 Sunnyside Avenue, Haworth Hall Lawrence KS 66045 USA
3. Department of Geosciences; University of Wisconsin-Milwaukee; 3029 N. Maryland Avenue Milwaukee WI 53211 USA