Browsing Volume 33 1997 by Issue Date
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ItemThe BPI - 50 years of palaeontological activity(Bernard Price Institute for Palaeontological Research, 1997) Rubidge, Bruce S.The Bernard Price Institute for Palaeontological Research at the University of the Witwatersrand was established from an endowment made by Bernard Price in 1945. Now, a mere 50 years later, the Institute ranks as a prominent palaeontological research centre in Africa. It curates large collections of fossils including Karoo reptiles, mammals from the Makapansgat valley and other Plio-Pleistocene sites, invertebrates from the Bokkeveld and Zululand, and has a large palaeobotany herbarium. The Institute produces the journal Palaeontologia africana, the only journal in Africa dedicated to the publication of palaeontological papers. The BPI is closely affiliated to the Department of Palaeontology and Palaeoenvironmental Studies, the only department of palaeontology at a South African University. During the 50 years of its existence the BPI has played an important role in the advancement and dissemination of palaeontological knowledge in southern Africa. ItemTowards new paradigms in Permo-Triassic Karoo palaeobotany (and associated faunas) through the past 50 years(Bernard Price Institute for Palaeontological Research, 1997) Anderson, Heidi Marguerite; Anderson, John MalcomAdvances through the past 50 years (1945 to 1995) have shown, indisputably, that the Permo-Triassic Karoo flora (with associated insect faunas) is as important globally as is the famous tetrapod fauna. We justify this in regard to the three most productive horizons: the Middle Ecca (Early to Middle Permian), Estcourt Formation (Late Permian) and the Molteno Formation (Late Triassic). The Middle Ecca gained international prominence through the collections ofLe Roux from 1946 to 1955 and the publications of Plum stead from 1952 to 1962, which demonstrated for the first time a wide suite of fructifications found attached to Glossopteris leaves. Similar finds have subsequently been made throughout the rest of the Gondwana Permian. The Glossopteridales remain unique among fossil gymnosperm orders in yielding such a diverse range of articulated (organically attached) foliage/fruit material. The Estcourt Formation offers an unparalleled opportunity to study ecosystems of the Late Permian prior to the extinction event terminating the period. The formation is singular in that it yields an excellent, well known flora and insect fauna (sampled primarily by van Dijk from 1957 to 1984 and Benecke, Anderson and Anderson from 1969 to 1971) in conjunction with a diverse tetrapod fauna. The Molteno Formation provides a window onto Late Triassic plant and insect communities, at around the time of origin of the mammals, dinosaurs and birds, perhaps unrivalled elsewhere in the world. The extensive/intensive collections of the Molteno (made by Anderson and Anderson over nearly 30 years from 1967 to the present) allow the application of a statistical projection hinting at the extraordinary possibility of biodiversities akin to those of today. The gymnosperms ofthe Late Triassic may well have been as rich in species and orders as are the extant angiosperms (flowering plants). ItemCretaceous fossils from the Orapa Diamond Mine(Bernard Price Institute for Palaeontological Research, 1997) Rayner, R. J.; Bamford, M. K.; Brothers, D. J.; Dippenaar-Schoeman, A. S.; McKay, I. J.; Oberprieler, R. G.; Waters, S. B.The Orapa kimberlite pipe, situated in north-central Botswana, is well-known for its rich reserves of diamonds. It is indeed one of the largest and richest diamond mines in the world. The kimberlite magma transporting the diamonds from the upper mantle erupted through a sequence ofKaroo-aged rocks before the deposition ofthe Kalahari Sands. This eruption has been radiometrically dated at early Late Cretaceous (Cenomanian-Coniacian). When volcanism ceased, a succession of epiclastic crater lake sediments was deposited above the kimberlite plug. Analysis of these sediments, which mostly comprise the results of mudflows and debris flows and fmer sediments during quiescenttimes, suggests that most of the sediments within the crater were deposited rapidly as mass flows, and were therefore mobilised soon after the volcanic eruption. Buried within the fine-grained sediments is a unique assemblage of fossils including flowering plants and many whole-bodied insects. The fossils are commonly exquisitely preserved in extremely fine-grained mudstone. Interpretation of the sedimentary facies and fossils is that the mid-Cretaceous climate of central Botswana was temperate, seasonal and wet, and the area surrounding the crater was forested. The fossils represent the recovery of the biota of the area after the violent eruptions of Orapa and other nearby kimberlite fissures and pipes. The fossils have contributed considerably to our understanding of mid-Cretaceous insects and flowering plants and suggest intimate relationships between the two at an early stage in the radiation of flowering plants. It seems that southern Gondwana (including southern Africa) was a centre of diversification for both insects and angiosperms in the mid-Cretaceous. ItemContributions in the field of palaeopalynology at the Bernard Price Institute, past, present and future(Bernard Price Institute for Palaeontological Research, 1997) MacRae, C. S.; Aitken, G. A.A brief chronological summary of the palynological research carried out by students and past members of the staff at the Bernard Price Institute for Palaeontological Research is presented. The contribution that each of these studies has made to the understanding of stratigraphic relationships in the southern African region is highlighted. A correlation chart of palynological biozones documented from South African localities is presented (Table 1). ItemCoaxing history from the rocks: The contribution of the BPI (palaeontology)(Bernard Price Institute for Palaeontological Research, 1997) Raath, M. A.From humble beginnings at the conclusion of the Second World War, the Bernard Price Institute for Palaeontological Research has developed into a major centre of palaeontological research and training whose contribution extends far beyond the borders of South Africa. Over the 50 years of its existence it has amassed large collections offossils from most of the fossiliferous deposits of South Africa, covering a large segment of geological time and a broad sweep of the diversity oflife. These collections have provided the foundation for ongoing research by its staff and students, as well as by visiting scientists from many other parts of the world. As a component of the University of the Witwatersrand, the Institute incorporates the only separate teaching department of palaeontology in any South African university, through which a steady stream of undergraduate and graduate students has passed over the years. Many of those students now occupy senior research and management positions in institutions and corporations scattered across the world. Under its current leadership, the Institute looks set fair for the next 50 years of solid contribution to world palaeontology. ItemAssessing the biology of fossil vertebrates through bone histology(Bernard Price Institute for Palaeontological Research, 1997) Chinsamy, AnusuyaSoon after death and burial of an animal, the organic components of bone generally decay. The closely associated inorganic components (mainly apatite) are more resilient and even after millions of years of burial, preserve the spatial organisation of the collagen fibres and hence the structure of the bone. In the past fossil bone histology has been the subject of substantial research. Such studies have included a wide array of extinct vertebrates including fishes, amphibians, pelycosaurs, therapsids, ichthyosaurs, pterosaurs, and dinosaurs. The relative rate ofbone formation is indicated by the texture of the fibrillar matrix, while the overall nature of the primary compact bone provides a direct assessment of whether bone deposition was continuous or interrupted. The amount of secondary bone formation depicts the extent of primary bone resorption and subsequent redeposition. In addition, the internal organisation of bone indicates remodelling and relocation processes of growth, including functional adaptations of the bone morphology. Thus, osteohistology reflects ontogeny, growth dynamics, biomechanical adaptations, as well as various events that punctuate the life history of an animal. ItemSome little known chapters in the early history of the Makapansgat fossil hominid site(Bernard Price Institute for Palaeontological Research, 1997) Tobias, Phillip V.The opening up of the Makapansgat Limeworks deposit as an early hominid site was closely linked with the early years of the Bernard Price Institute for Palaeontological Research. Much of the history of the events leading up to James Kitching's recovery of the fIrst australopithecine partial calvaria in 1947 is either scattered or remains unrecorded. An attempt is made here to recount the roles ofW.I. Eitzman, R.A. Dart, R. Broom, C. van Riet Lowe, B.D. Malan, J. Kitching and his brothers Ben and Scheepers, R.J. Mason and Dr. Bernard Price in the revelation of the scientifIc signifIcance of those Limeworks and of other important sites in the area, the Cave of Hearths, Rainbow Cave, Historic Cave and Mwulu's Cave. The historical part played by six student expeditions to the area in 1945-1947 is described. Save for palaeontological papers by J.S. Jensen, O.D.v.d.S. Mollett and M.M. Dale, and archaeological ones by P. V. Tobias, the major impact of these ventures has not hitherto been analysed. It is shown that the fIrst expedition was responsible for drawing R.A. Dart back into the fIeld after 20 years of virtual abstinence, for setting afoot a series of further ventures in that area, and for leading to the uncovering ofthe fIrst hominid specimens from the Limeworks from 1947 onwards. New evidence is presented bearing on the relationships between R.A. Dart and R. Broom, which suffered strain after both the Sterkfontein discoveries of cercopithecids in 1936 and those at the Makapansgat Limeworks in 1945. A note is added about the original extensive report on the fIrst student expedition, which independent referees had recommended to the Wits University Principal, H.R. Raikes, should be published. As a result of the unexplained loss of this report, at or en route to the publisher, it remains unpublished to this day. ItemThe contribution of Raymond Dart to the development of cave taphonomy(Bernard Price Institute for Palaeontological Research, 1997) BrainThe basic principles of African cave taphonomy were formulated in 1976, but twenty years earlier, Raymond Dart embarked on a pioneering taphonomic investigation into a hominid-bearing fossil assemblage from the Makapansgat Limeworks cave. He asked the questions that are typically addressed in contemporary cave-taphonomic studies, such as: how did the bones find their way into the cave? From what animals were the bones derived? What parts of the skeleton are represented and what damage have the bones suffered? What can be said about the behaviour of the hominids and other animals whose remains are preserved in the cave? Dart concluded that hominids had been responsible for collecting the very large number of bones preserved in the Member 3 grey breccia unit. He set up a theory ofthe "osteodontokeratic" culture of Australopithecus and drew some remarkable conclusions about the nature and behaviour of early hominids. These conclusions, presented in powerful prose, provoked a good deal of subsequent research that set the discipline of cave taphonomy on its course. ItemThe role of fossils in interpreting the development of the Karoo Basin(Bernard Price Institute for Palaeontological Research, 1997) Hancox, P. J.; Rubidge, B. S.The Permo-Carboniferous to Jurassic aged rocks off the main Karoo Basin of South Africa are world renowned for the wealth of synapsid reptile and early dinosaur fossils, which have allowed a ten-fold biostratigraphic subdivision of the Karoo Supergroup to be erected. The role of fossils in interpreting the development of the Karoo Basin is not, however, restricted to biostratigraphic studies. Recent integrated sedimentological and palaeontological studies have helped in more precisely defining a number of problematical formational contacts within the Karoo Supergroup, as well as enhancing palaeoenvironmental reconstructions, and basin development models. ItemThe importance of Karoo fossils in the search for mammal origins.(Bernard Price Institute for Palaeontological Research, 1997) Gow, Chris E.It has long been known that mammals belong to the group Synapsida (more familiar to most in South Africa by the now discredited term Mammal-like Reptiles), a group with a long fossil history, much of which was first established from the Karoo. In palaeontology mammals are traditionally defmed by the possession of a squamosal/dentary jaw joint, as opposed to the quadrate/articular jaw joint of non-mammalian tetrapods. This paper recounts some of the advances in our knowledge of the therapsids (advanced synapsids) over the past 50 years, including the discovery of a sequence offorms leading to those which possess both premammalian and mammalianjaw hinges, transitional forms which thus by defInition qualify as mammals. Briefmention is made of some historical aspects of phylogenetic interpretation, pointing out that some early workers following Darwin, were as aware of the central role of species in phylogenetics as are the disciples of Hennig and Eldredge and Gould. Briefreference is made to the crown group defmition of mammals proposed by Rowe (1988), as it contrasts with the traditional character-based definition. Finally, it is encouraging that modem workers are not only as aware of the problems of distinguishing homology and homoplasy as were earlier workers, but are starting to acknowledge the importance of missing information. In this way, just as the double jaw joint was first predicted and then found, we can actively seek to fill some of the many remaining gaps in our knowledge.