Affiliation: | 1. Department of Geosciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA;2. Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, D.C. 20013, USA;3. Museo Paleontológico Egidio Feruglio, Consejo Nacional de Investigaciones Científicas y Técnicas, Trelew 9100, Chubut, Argentina;4. Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, New York 14853, USA |