1. Centro de Astrobiología (CSIC/INTA), ctra. de Torrejón a Ajalvir km 4, 28850 Torrejón de Ardoz, Spain; ,
2. Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, no. 39 East Beijing Road, Nanjing 210008, China;
3. Centre of Biology, Earth and Environmental Sciences, University of West Bohemia at Plzen˘, Plzen˘ 30619, Czech Republic;
4. Sprigg Geobiology Center, School of Earth & Environmental Sciences, University of Adelaide, SA 5005, Australia;
5. Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013-7012, USA;