Volume 32 1995

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    Palaeontologia africana Volume 32
    (Bernard Price Institute for Palaeontological Research, 1995)
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    African fossil Lissamphibia
    (Bernard Price Institute for Palaeontological Research, 1995) van Dijk, D. E.
    The Anura (Frogs and Toads) are represented in Africa and associated regions by fossils of every epoch from the Cretaceous to the Holocene. Pipid frogs of African affinity are known from the Early Cretaceous of Israel and Later Cretaceous of South America and Africa; those of Israel and South America have been well-studied, but only one from Africa has been: Eoxenopoides reuningi from Namaqualand. Two well-studied Palaeocene frogs of South America, Shelania pascuali and Xenopus romeri, have affinities with the African pipids. Apart from a Miocene assemblage from North Africa (including pipids, which are now exclusively sub-Saharan) and one species from Namibia, Xenopus stromeri, the fossil African anurans remain largely unstudied. Deposits in which the African anuran fossils occur represent crater lakes, other lacustrine deposits, including lacustrine tuffs, river terraces, deltas, estuarine/lagoon zones, karst landscapes and archaeological sites; data are not available for several of the recorded fossils. No fossils in Africa appear to have been definitely ascribed to the Urodela or Caecilia.
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    Quantifying morphological variability within extant mammalian species
    (Bernard Price Institute for Palaeontological Research, 1995) Thackeray, J. F.; Helbig, J.; Moss, S.
    In this study we attempt to establish a baseline for measuring species variability in the palaeontological record by using linear regression analysis on sets of measurements from extant mammalian species (males and females within species). In particular, this study explores the standard error of the m-coefficient (s.e.m) , derived from linear regression analyses associated with equations of the form y = mx + c, to quantify the degree of morphological variability within extant mammalian species. The slope m generally centres around 1.00. Even though the species in this study range in size from small rodents to large ungulates, s.e'm values show a normal distribution around a mean of 0.035 . The approach outlined here has potential application in palaeontological contexts where there is uncertainty about any two specimens being conspecific.
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    An aggregation of juvenile Youngina from the Beaufort Group, Karoo Basin, South Africa
    (Bernard Price Institute for Palaeontological Research, 1995) Smith, Roger M. H.; Susan, E. Evans
    An assemblage of five fully-articulated juvenile skeletons of Youngina has been recovered from the Late Permian strata of the south-western Karoo Basin. These 12-cm-long skeletons are not only the first articulated juveniles of this taxon, but also the oldest yet found in the Karoo Basin. They are preserved in overbank mudrocks of the Hoedemaker Member (Beaufort Group, Adelaide Subgroup) on the farm Leeukloof 43 in the Beaufort West district. Although they are estimated to be some three million years older than previously described Youngina, these specimens show no significant skeletal differences. The high degree of articulation and the spatial arrangement of these skeletons in a dish-shaped hollow is compelling evidence for them having huddled together within an underground burrow. Taphonomic analysis of associated fossils indicates that this was probably a mechanism to reduce water loss during drought on the ancient Karoo floodplains .
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    Fossil eggs and Cenozoic continental biostratigraphy of Namibia
    (Bernard Price Institute for Palaeontological Research, 1995) Senut, Brigitte; Pickford, Martin
    One kind of aepyornithoid and six kinds of struthious eggshells have been found in Cenozoic deposits of Namibia. Field evidence indicates that the six struthious egg types are time successive, and they thus form a useful basis for determining the relative stratigraphic positions of sites at which they occur. Their placement in the geological time scale has been partly tied down by reference to the biostratigraphic position of mammals that occur in association with them.