Browsing Volume 32 1995 by Issue Date
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ItemA new find of Megalotragus priscus (Alcelaphini, Bovidae) from the central Karoo, South Africa(Bernard Price Institute for Palaeontological Research, 1995) Brink, J. S.; de Bruiyn, H.; Rademeyer, L. B.; van der Westhuizen, W. A.We document the occurrence of the Florisian, or late Quaternary, form of the giant alcelaphine, Megalotragus priscus, from dongas on the Ongers River, near Britstown in the central Karoo. This is significant as it confirms the occurrence of the species in the Karoo and it suggests significantly wetter environments and productive grasslands in the central Karoo in pre-Holocene times. The present-day Karoo environment did not maintain populations of large ruminant grazers similar to M. priscus, and other specialized Florisian grazers, prior to the advent of agriculture and pasture management. Aridification in recent times is the likely cause of changes in grassland quality and the local dissappearance of these animals, if not their extinction. ItemMore fossil wood from the Namaqualand coast, South Africa; onshore material.(Bernard Price Institute for Palaeontological Research, 1995) Bamford, Marion K.; Corbett, Ian B.Fossil wood was collected from a palaeo-beach sequence on the farms Sandkop, Oubeep and adjacent State land, on the Namaqualand (west) coast of South Africa. Of the 14 samples sectioned only 5 were well enough preserved to describe and identify to species level. The woods are podocarpaceous and have been assigned to the taxa Podocarpoxylon cf. umzambense, Mesembrioxylon woburnense, M. stokesi and Mesembrioxylon sp. The samples are Lower Cretaceous in age and were most probably reworked a number of times into successively younger palaeoshoreline deposits. The same species occurred in the offshore sediments, therefore indicating a wider area of "woodland" and further evidence of extensive shelf erosion by subsequent marine transgressions and regressions. ItemPreliminary analysis of the fauna from Buffalo Cave, northern Transvaal, South Africa(Bernard Price Institute for Palaeontological Research, 1995) Kuykendall, K. L.; Toich, C. A.; McKee, J. K.Systematic excavations at Buffalo Cave in the Makapan Valley were begun in October 1993. This paper presents our preliminary analysis of the faunal assemblage from this site, including new in situ fossils and the collections which have been housed at the Bernard Price Institute, Palaeontology since the 1940's. Our palaeoecological reconstruction suggests that the local environment at Buffalo Cave at the time of deposition was an open country grassland or savanna, including a high proportion of alcelaphine bovids and other grazing fauna. However, the presence of other taxa, particularly of tragelaphines, hippotragines, and reduncines, may indicate that a more wooded habitat including a local water source, could also have been part of the Buffalo Cave environment during some part of its depositional history. The fauna overall indicates that deposition occurred during the Pleistocene, rather than the Pliocene. Thus, the environmental and temporal information presently available suggests that the Buffalo Cave fauna represents an environment and time period distinct from other sites in the Makapansgat Valley (i.e., the Limeworks and Cave of Hearths). ItemA preliminary assessment of the micromammalian remains from Gladysvale Cave, South Africa(Bernard Price Institute for Palaeontological Research, 1995) Avery, D. M.New micromammalian material from Gladysvale Cave has recently been collected by L.R. Berger and A.W. Keyser. The sample contains representatives of 29 species, of which five are insectivores, seven are bats and the remainder are rodents. Apart from one specimen which is possibly referable to the extinct species, Proodontomys cookei, the material appears to belong to extant species. Proportional representation of species varies between units. This may indicate different environmental conditions and therefore different ages for the deposits concerned. It could equally reflect different agents of accumulation. Taphonomic work should establish whether this is the case. In general terms, environmental conditions were apparently similar to those of today. ItemFossil eggs and Cenozoic continental biostratigraphy of Namibia(Bernard Price Institute for Palaeontological Research, 1995) Senut, Brigitte; Pickford, MartinOne 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. ItemQuantifying 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. ItemAfrican 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. ItemAn 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. EvansAn 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 . ItemDentition and feeding niche of Endothiodon (Synapsida; Anomodontia).(Bernard Price Institute for Palaeontological Research, 1995) Latimer, E. M.; Gow, C. E.; Rubidge, B. S.The cranial morphology and extensive dentition of the dicynodont therapsid Endothiodon are different from those of any other dicynodont and it clearly had a different feeding niche. Recently prepared material from Mozambique which has relatively well preserved dentition has revealed that the mode of tooth replacement of Endothiodon differs in the upper and lower jaws. The very high and narrow vaulted palate with a close fitting, pointed lower jaw indicates that Endothiodon had a small mouth with muscular cheeks and extensive cheek pouches, suggesting a browsing feeding niche. ItemFurther chronological seriations of southern African Pliocene and Pleistocene mammalian faunal assemblages(Bernard Price Institute for Palaeontological Research, 1995) McKee, Jeffrey K.Mammalian fossil assemblages from Pliocene and Pleistocene sites of southern Africa have recently been seriated in order to establish a relative chronology (McKee et al. 1994). Although an order was inferred for 17 site assemblages of fossil mammals, only ten sites could be seriated at a time. The logistical seriation method has now been modified to handle a greater number of sites at once. Seriations were run on a matrix of Faunal Resemblance Index values for an updated list of time-sensitive mammals of 18 fossil site assemblages. In addition, each assemblage was systematically excluded from analysis in successive seriations to test the robusticity of the method against the influence of individual assemblages. The seriations gave largely consistent results, with the exception of the terminal Pleistocene sites. The most likely chronological sequence inferred from the logistical seriations alone, with corrections for stratigraphic considerations, is: Makapansgat Member 3, Makapansgat Member 4, Taung Hrdlicka deposits, Sterkfontein Member 4, Kromdraai B, Sterkfontein Member 5 (in part), Kromdraai A, Swartkrans Member 1, Swartkrans Member 2, Swartkrans Member 3, Gondolin, Plovers Lake, Cornelia, Elandsfontein Main Site, Florisbad/Equus Cave, Cave of Hearths and Klasies River Mouth. ItemKaroo supergroup palaeontology of Namibia and brief description of a Thecodont from Omingonde(Bernard Price Institute for Palaeontological Research, 1995) Pickford, MartinKaroo strata crop out extensively in Namibia. Numerous and diverse fossils have been collected from three areas - Karasberg, Kalahari and Huab Karoo basins. Although a great deal of research has been done on these strata and their fossil content, the literature is scattered and no publication has been devoted to a detailed review of what has been achieved. This paper presents a review based principally on a literature search allied to personal experience of some of the fossils and field trips to a few localities. It cannot pretend to be an in-depth review. The Namibian Karoo outcrops are so extensive and the palaeontological remains so diverse, that several years of intensive research would be required to achieve such a work. Tragically, many of the fossils mentioned in the text have been lost or their whereabouts are unknown. A small sample of fossils is housed in the Geological Survey Museum, Windhoek, and other fossils are known to be curated by the South African Museum, Cape Town, the Bernard Price Institute for Palaeontological Research, Witwatersrand University and the Geological Survey of South Africa, Pretoria. A thecodont from the Omingonde Formation (Upper Triassic) is described briefly.