1 Phytoplankton dynamics from the Cambrian Explosion to the onset of the Great 2 Ordovician Biodiversification Event: a review of Cambrian acritarch diversity 3 4 Hendrik Nowaka, Thomas Servaisa,*, Claude Monneta, Stewart G. Molyneuxb, Thijs R. A. 5 Vandenbrouckea 6 7 a Evo-Eco-Paleo, UMR 8198, CNRS-University of Lille, Avenue Paul Langevin, bâtiment SN5, 8 59655 Villeneuve d’Ascq Cedex, France 9 b Honorary Research Associate, British Geological Survey Environmental Science Centre, Nicker 10 Hill, Keyworth, Nottingham, NG12 5GG, United Kingdom 11 12 * Corresponding author. Tel.: +33 320337220. 13 E-mail addresses:
[email protected] (H. Nowak), thomas.servais@univ- 14 lille1.fr (T. Servais),
[email protected] (C. Monnet),
[email protected] (S.G. Molyneux), 15
[email protected] (T.R.A. Vandenbroucke). 16 17 Abstract: Most early Palaeozoic acritarchs are thought to represent a part of the marine 18 phytoplankton and so constituted a significant element at the base of the marine trophic chain 19 during the ‘Cambrian Explosion’ and the subsequent ‘Great Ordovician Biodiversification Event.’ 20 Cambrian acritarch occurrences have been recorded in a great number of studies. In this paper, 21 published data on Cambrian acritarchs are assembled in order to reconstruct taxonomic diversity 22 trends that can be compared with the biodiversity of marine invertebrates. We compile a database 23 and calculate various diversity indices at global and regional (i.e. Gondwana or Baltica) scales. The 24 stratigraphic bins applied are at the level of the ten Cambrian stages, or of fourteen commonly used 25 biozones in a somewhat higher resolved scheme.