Wicander, R. and Playford, G., 2017. Organic-walled microphytoplankton assemblage of the Middle Devonian (Givetian) Arkona, Hungry Hollow and Widder formations, Ontario, Canada: biostratigraphic and palaeogeographic significance . Boletín Geológico y Minero, 128 (4): 839-883 ISSN: 0366-0176 DOI: 10.21701/bolgeomin.128.4.001 Organic-walled microphytoplankton assemblage of the Middle Devonian (Givetian) Arkona, Hungry Hollow and Widder formations, Ontario, Canada: biostratigraphic and palaeogeographic significance R. Wicander (1, 2) and G. Playford (2) (1) Department of Earth and Atmospheric Sciences, Central Michigan University, Mount Pleasant, Michigan, U.S.A. 48859.
[email protected] (2) School of Earth and Environmental Sciences, The University of Queensland, Brisbane, Q 4072, Australia.
[email protected] ABSTRACT A diverse and abundant organic-walled microphytoplankton assemblage, consisting of 49 species of acri - tarchs, prasinophyte phycomata and chitinozoans, was recovered from a 13.3 m-section of the Middle Devonian (Givetian) Arkona, Hungry Hollow and Widder formations at Hungry Hollow, Ontario, Canada. Close similarity exists between this assemblage and others described previously from the Givetian of North America. Marine palynofloras of comparable age from elsewhere in North America share between 59–96% of the species identified in the present assemblage, thus testifying to its stratigraphic-correlative applicability in a regional context. Species widely occurring in North America and typically Givetian (although not restricted therein) include: Arkonites bilixus, Cymatiosphaera canadense, Diexallophasis simplex, Duvernaysphaera angelae, D. tenuicingulata, Estiastra rhytidoa, Exochoderma arca, Gorgonisphaeridium inflatum, Hapsidopalla chela, Leiofusa pyrena, Muraticavea munifica, Oppilatala sparsa, Palacanthus ledanoisii , Polyedryxium ambitum, Staplinium cuboides, Tyligmasoma alargada, Uncinisphaera acantha, Veryhachium pastoris, Villosacapsula compta and V.