FOSSIL CALIBRATIONS FOR THE ARTHROPOD TREE OF LIFE

Fossil age data and molecular sequences are increasingly combined to establish a timescale for the Tree of Life. Arthropods, as the most species-rich and morphologically disparate animal phylum, have received substantial attention, particularly with regard to questions such as the timing of habitat shifts (e.g. terrestrialisation), genome evolution (e.g. gene family duplication and functional evolution), origins of novel characters and behaviours (e.g. wings and flight, venom, silk), biogeography, rate of diversification (e.g. Cambrian explosion, insect coevolution with angiosperms, evolution of crab body plans), and the evolution of arthropod microbiomes. We present herein a series of rigorously vetted calibration fossils for arthropod evolutionary history, taking into account recently published guidelines for best practice in fossil calibration. These are restricted to Palaeozoic and Mesozoic fossils, no deeper than ordinal taxonomic level, nonetheless resulting in 80 fossil calibrations for 102 clades. This work is especially timely owing to the rapid growth of molecular sequence data and the fact that many included fossils have been described within the last five years. This contribution provides a resource for systematists and other biologists interested in deep-time questions in arthropod evolution. ABBREVIATIONS AMNH American Museum of Natural History AMS Australian Museum, Sydney AUGD University of Aberdeen BGR Bundesanstalt fur Geowissenschaften und Rohstoffe, Berlin BMNH The Natural History Museum, London CNU Key Laboratory of Insect Evolutionary & Environmental Change, Capital Normal University, Beijing DE Ulster Museum, Belfast ED Ibaraki University, Mito, Japan FMNH Field Museum of Natural History GMCB Geological Museum of China, Beijing GSC Geological Survey of Canada IRNSB Institut Royal des Sciences Naturelles de Belgique, Brussels KSU Kent State University Ld Musee Fleury, Lodeve, France LWL Landschaftsverband Westfalen-Lippe-Museum fur Naturkunde, Munster MACN Museo Argentino de Ciencias Naturales, Buenos Aires MBA Museum fur Naturkunde, Berlin MCNA Museo de Ciencias Naturales de Alava, Vitoria-Gasteiz, Alava, Spain MCZ Museum of Comparative Zoology, Harvard University MGSB Museo Geologico del Seminario de Barcelona MN Museu Nacional, Rio de Janeiro MNHN Museum national d'Histoire naturelle, Paris NHMUK The Natural History Museum, London NIGP Nanjing Institute of Geology and Palaeontology NMS National Museum of Scotland OUM Oxford University Museum of Natural History PBM Palaobotanik Munster PIN Paleontological Institute, Moscow PRI Paleontological Research Institution, Ithaca ROM Royal Ontario Museum SAM South Australian Museum, Adelaide SM Sedgwick Museum, University of Cambridge SMNK Staatliches Museum fur Naturkunde, Karlsruhe SMNS Staatliches Museum fur Naturkunde, Stuttgart TsGM F.N. Chernyshev Central Geologic Prospecting Research Museum, St. Petersburg UB University of Bonn USNM US National Museum of Natural History, Smithsonian Institution UWGM University of Wisconsin Geology Museum YKLP Yunnan Key Laboratory for Palaeobiology, Yunnan University YPM Yale Peabody Museum ZPAL Institute of Paleobiology, Polish Academy of Sciences, Warsaw.