Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138, United States; Centro de Astrobiología (INTA-CSIC), INTA Campus, 28850 Torrejón de Ardoz, Spain; Departamento de Estratigrafía, Facultad de Ciencias Geológicas, Universidad Complutense de Madrid, 28041 Madrid, Spain; Museo Geominero, Instituto Geológico y Minero, 28003 Madrid, Spain; Division of Geological and Planetary Sciences, California Institute of Technology, CA 91125, United States; Department of Geosciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, United States; The Agouron Institute, Pasadena, CA 91106, United States; Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, 28048 Madrid, Spain; Sprigg Geobiology Centre, School of Earth and Environmental Sciences, University of Adelaide, SA 5005, Adelaide, Australia; Max-Planck-Institute for Biogeochemistry, 07745 Jena, Germany; MARUM, Universität Bremen, 28359 Bremen, Germany; Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, United States