The planktonic foraminifera of the Jurassic. Part I: material and taxonomy
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The planktonic foraminifera of the Jurassic. Part I: material and taxonomy Felix Gradstein1,2 • Andrew Gale2 • Ludmila Kopaevich3 • Anna Waskowska4 Algimantas Grigelis5 • Larisa Glinskikh6
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Received: 21 February 2017 / Accepted: 7 April 2017 / Published online: 30 May 2017 Ó Akademie der Naturwissenschaften Schweiz (SCNAT) 2017
Abstract The taxonomy is modernized and updated for Jurassic planktonic foraminifera using all available literature and stratigraphic series of sediment samples from Canada, Portugal, France, Switzerland, Poland, Lithuania, Russia and Dagestan. The regional stratigraphy of all sampled sections is outlined. Many of the 65–200 lm sample residues yielded well-preserved free specimens, with local assemblages containing up to six species. Thin sections were studied also but do not allow detailed taxonomy. Two genera are described: Globuligerina and Conoglobigerina. Globuligerina probably appeared in the late Toarcian (late Early Jurassic) and Conoglobigerina first occurred in middle Oxfordian (early Late Jurassic). A principal difference between Globuligerina and Conoglobigerina is that the former has a smooth to pustulose wall surface texture and the Editorial handling: Daniel Marty. This study is dedicated to the memory of Dr. Olga Pazdrowa ( ), Poland (Photograph 1), who in 1969 presented the Earth Sciences with a fine description of a new and spectacular find of Jurassic planktonic foraminifera (Globigerina bathoniana sp. nov.) in her study entitled ‘Bathonian Globigerina from Poland’. & Felix Gradstein [email protected]
latter a reticulate wall surface texture. Within the two genera, ten species are described, including from older to younger: Globuligerina dagestanica (Morozova), G. avariformis (Kasimova), G. balakhmatovae (Morozova), G. oxfordiana (Grigelis), G. bathoniana (Pazdrowa), G. jurassica (Hofman), G. oxfordiana (Grigelis) calloviensis Kuznetsova emended, G. tojeiraensis Gradstein, Conoglobigerina helvetojurassica (Haeusler), C. grigelisi Gradstein and C. gulekhensis (Gorbachik and Poroshina). The coarsely perforate ‘Globuligerina’ stellapolaris needs more investigation to establish its identity as a Jurassic or a Late Cenozoic taxon (Gradstein 2017a). Globuligerina balakhmatovae, G. oxfordiana and G. bathoniana occur from Bajocian through early Kimmeridgian, or even Tithonian. Subtle morphological trends may refine stratigraphic usage. Other taxa have shorter stratigraphic ranges. Nineteen plates and ten type species figures detail morphology of all taxa. For key taxa, both the types and specimens from other localities are illustrated. Keywords Jurassic Planktonic foraminifera Globuligerina Conoglobigerina Europe Canada Russia Dagestan
1
Natural History Museum, University of Oslo, 0318 Oslo, Norway
Introduction
2
SEES, University of Portsmouth, Portsmouth PO1 3QL, UK
3
Geological Faculty, Lomonosov Moscow State University, Leninskie Gory, GSP-1, 119991 Moscow, Russian Federation
4
AGH Akademia Go´rniczo-Hutnicza, al. Mickiewicza 30, 30-059 Krako´w
