Volume 46 December 2011

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    Palaeontologia africana Volume 46
    (Bernard Price Institute for Palaeontological Research, 2011)
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    Cretaceous biozonation based on terrestrial palynomorphs from two wells in the offshore Orange Basin of South Africa
    (Bernard Price Institute for Palaeontological Research, University of the Witwatersrand, 2011-12) Sandersen, A.; Scott, L.; McLachlan, I.R.; Hancox, P.J.
    The C-B1 and O-A1 petroleum exploration wells were drilled by SOEKOR Pty Ltd in 1988 and 1992, respectively, in the Orange Basin off the west coast of South Africa. A palynological analysis of the Cretaceous interval intersected by the two wells, for which the ages were adopted from foraminiferal studies, provides new information on the biostratigraphy and also on reconstructions of the Cretaceous palaeoflora and palaeoenvironment. The spores and pollen used in this study were extracted from over 500 samples of conventional cores, side-wall cores and ditch-cuttings. The identified terrestrial palynoflora includes 41 species of angiosperm and gymnosperm pollen, 85 species of fern and bryophyte spores, and two monolete spore taxa. Several of the pollen and spore taxa are possibly new species. Five palynological zones were established for each of the two wells, which are separated by a latitudinal distance of 300 km. Within the Early Cretaceous intervals of the two wells, there is a considerable degree of similarity in the palynological assemblages, which suggests that the terrestrial plant communities were relatively uniform. For the Late Cretaceous interval, however, there are marked differences suggesting that the plant communities had become more diverse and also that the palynomorphs were being supplied from separate geographical areas.
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    A structural re-interpretation and revision of the type material of the glossopterid ovuliferous fruitification Scutum from South Africa
    (Bernard Price Institute for Palaeontological Research, University of the Witwatersrand, 2011-12) Prevec, Rose
    The Early Permian glossopterid fructification Scutum, described by Edna Plumstead in the 1950s from the Vereeniging locality in the Karoo Basin of South Africa, was one of the first glossopterid seed-bearing organs to be found in organic attachment to Glossopteris leaves. Examination of the type material necessitated a revision of this plant fossil genus and a re-evaluation of described South African species. Key characteristics of the genus are the broad and prominent wing, and a low receptacle length to width ratio (<2:1). Specimens of South African Scutum are currently attributed to three species, from two localities, but display intergrading morphological features that can be reasonably accommodated within a single species, S. leslii. Three-dimensional interpretation and reconstruction of impression fossils of Scutum fructifications preserved in attachment to Glossopteris leaves confirms that the seed-bearing surface of the receptacle faces the adaxial surface of the subtending leaf. The nature of the seed scars on the receptacle and their relationship to the peripheral wing of the fructifications is clarified.