The Devonian nekton revolution

Authors

  • CHRISTIAN KLUG,

  • BJÖRN KRÖGER,

  • WOLFGANG KIESSLING,

  • GARY L. MULLINS,

  • THOMAS SERVAIS,

  • JIŘÍ FRÝDA,

  • DIETER KORN,

  • SUSAN TURNER


Christian Klug [chklug@pim.uzh.ch], Paläontologisches Institut und Museum, Universität Zürich, Karl Schmid-Strasse 4, CH-8006 Zürich, Switzerland; Björn Kröger [bjoekroe@gmx.de], Wolfgang Kiessling [wolfgang.kiessling@museum.hu-berlin.de] and Dieter Korn [dieter.korn@museum.hu-berlin.de], Museum für Naturkunde, Humboldt-Universität zu Berlin, Invalidenstraße 43, D-10115 Berlin, Germany; Gary L. Mullins [acritarcha@hotmail.com], Department of Geology, The University of Leicester, University Road, Leicester, LE1 7RH, UK; Thomas Servais [thomas.servais@univ-lille1.fr], Laboratoire de Paléontologie et Paléogéographie du Paléozoïque, UMR 8157 du CNRS, Université des Sciences et Technologies de Lille, SN5 Cité Scientifique, F-59655 Villeneuve d’Ascq, France; Jiří Frýda [bellerophon@seznam.cz], Faculty of Environmental Science, Czech University of Life Sciences, Kamýcká 129, 165 21 Praha 6 Suchdol, Czech Republic; Susan Turner [SueT@qm.qld.gov.au], School of Geosciences, Monash University, Box 28E, Vic 3800, and Queensland Museum Geosciences, 122 Gerler Road, Qld 4011, Australia; manuscript received on 9/4/2009; manuscript accepted on 10/9/2009.

Abstract

Klug, C., Kröger, B., Kiessling, W., Mullins, G.L., Servais, T., Frýda, J., Korn, D. & Turner, S. 2009: The Devonian nekton revolution. Lethaia, 10.1111/j.1502-3931.2009.00206.x

Traditional analyses of Early Phanerozoic marine diversity at the genus level show an explosive radiation of marine life until the Late Ordovician, followed by a phase of erratic decline continuing until the end of the Palaeozoic, whereas a more recent analysis extends the duration of this early radiation into the Devonian. This catch-all approach hides an evolutionary and ecological key event long after the Ordovician radiation: the rapid occupation of the free water column by animals during the Devonian. Here, we explore the timing of the occupation of the water column in the Palaeozoic and test the hypothesis that ecological escalation led to fundamental evolutionary changes in the mid-Palaeozoic marine water column. According to our analyses, demersal and nektonic modes of life were probably initially driven by competition in the diversity-saturated benthic habitats together with the availability of abundant planktonic food. Escalatory feedback then promoted the rapid rise of nekton in the Devonian as suggested by the sequence and tempo of water-column occupation. □Devonian, diversity, ecology, food webs, nekton, plankton, radiation.

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