Volume 27 1990
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Browsing Volume 27 1990 by Type "Article"
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Item The affinities of the early cynodont reptile, Nanictosaurus(Bernard Price Institute for Palaeontological Research, 1990) van Heerden, Jacques; Rubidge, BruceThis investigation into the anatomy of the four extant specimens of Nanictosaurus has revealed that there is one valid species, viz. N. kitchingi Broom 1936 which has two junior synonyms, viz. N. robustus Broom 1940 and N. rubidgei Broom 1940. The closest known relative of Nanictosaurus is the well-known cynodont Thrinaxodon liorhinus. The differences from Thrinaxodon and other early cynodonts are discussed and illustrated.Item Carnivore activity at Klasies River Mouth: a response to Binford(Bernard Price Institute for Palaeontological Research, 1990) Thackeray, J FrancisEnvironmental and behavioural factors contributed to variability in the relative abundance of Raphicerus (grysbok/steenbok) represented in Late Pleistocene and Holocene deposits at the complex of caves at Klasies River Mouth and at Nelson Bay Cave in the southern Cape Province, South Africa. Binford has used the relative abundance of Raphicerus in an index assumed to measure the degree of hunting by Middle Stone Age hominids. However, the occurrence of relatively high numbers of Raphicerus with leopards and baboons in some layers is likely to have been associated, at least in part, with leopard activity, particularly at times when relatively large ungulates were not common in the palaeoenvironment and when the cave sites were not frequently occupied by hominids with control over fire. Binford's indices are re-assessed in the light of other indices which are designed to identify assemblages that have a relatively high probability of having been accumulated by leopards and/or other carnivores.Item Clarification of Belemnopteris Feistmantel 1876, and description of a leaf of Belemnopteris pellvcida Pant and Choudhury 1977 found amongst a South African Ecca flora(Bernard Price Institute for Palaeontological Research, 1990) Kovacs-Endrody, EA leaf of Belemnopteris pellucida Pant and Choudhury 1977 was found for the first time in South Africa amongst an Ecca flora near Hammanskraal, about 30km north of Pretoria. The taxonomic status of Belemnopteris Feistmantel 1876 and the biostratigraphic correlation indicated by the presence of this genus is clarified.Item Devonian hyoliths in South Africa, and their palaeoenvironmental significance(Bernard Price Institute for Palaeontological Research, 1990) Hiller, NortonHyoliths, an extinct group of molluscan or mollusc-like invertebrates that secreted elongate conical shells, are relatively uncommon and often overlooked members of Middle Palaeozoic marine fossil assemblages. They have been recorded from a number of widespread localities in the argillaceous Gydo and Voorstehoek Formations of the Bokkeveld Group. Most of the specimens are crushed or are without opercula and other taxonomically important features of the aperture and therefore must remain indeterminate. The hyoliths occur in bioturbated mudstones along with brachiopods, trilobites, bivalves, gastropods, crinoids, cephalopods and conulariids. This assemblage is interpreted as representing an inner shelf community that occupied quiet waters below wave base seaward of the prograding Bokkeveld deltas. Unlike many of the other elements of the shelf community, the epifaunal, deposit-feeding hyoliths are not found in the shallower water communities and can be taken as diagnostic of the offshore environments.Item Dicynodonts and the end Permian event(Bernard Price Institute for Palaeontological Research, 1990) King, Gilian MPatterns of diversity changes in several groups of Late Permian South African terrestrial tetrapods are examined. Using data contained in Kitching (1977), histograms are presented which illustrate changes in a) total number of tetrapod genera per biostratigraphic zone; b) total number of therapsid genera per zone; c) total number of herbivore genera per zone; and d) total number of carnivore genera per zone. Herbivorous and carnivorous genera are categorized as comprising small, medium or large individuals and histograms which document changes in number of genera in each of these six categories per zone are presented. Potential sources of error inherent in the data are outlined. Broad changes in generic diversity are noted and possible explanations for these changes are presented. It is concluded that the present data do not provide overwhelming evidence for a rapid and catastrophic drop in terrestrial tetrapod diversity at the very end of the Permian, but do illustrate a gradual and continuing decrease from the middle of the Late Permian into the middle of the Triassic.Item Dinosaur tracks in Triassic Molteno sediments: the earliest evidence of dinosaurs in South Africa?(Bernard Price Institute for Palaeontological Research, 1990) Raath, Michael A; Kitching, James W; Shone, Russell W; Rossouw, G JA fossil tracksite containing well-preserved tridactyl footprints of bipedal theropod dinosaurs is reported from fluvial overbank deposits of Molteno age (Stormberg Group: Triassic) in the northeastern Cape Province, South Africa. They occur stratigraphically below the mudrocks of the Elliot Formation, in which dinosaur remains are comparatively common, and are taken to represent the earliest evidence for dinosaurs in South Africa. They also represent the earliest unequivocal evidence of tetrapods in Molteno deposits.Item A dinosaur trackway from the Purbeck Beds of Swanage, England(Bernard Price Institute for Palaeontological Research, 1990) Newman, B HDuring 1962 a dinosaur trackway was unearthed in a quarry of Upper Jurassic/Lower Cretaceous building-stone at Langton Maltravers near Swanage. The primary tracks had been removed initially but secondary impressions were still visible and these were marked with black paint. It was concluded that the prints were made by a tridactyl bipedal species of dinosaur, probably of megalosaurian type. A quantity of overburden covered part of the trackway and it was arranged for this to be removed so that the primary tracks could be collected. The trackway, which was 22 metres long as preserved, showed a somewhat sinuous gait of a true biped with no tail-drag and only occasional evidence of what may have been front foot impressions. Two individuals had made the footprints, walking on a similar course about one metre apart. The tracks of these two were collected, as was a third trackway which went off at an angle to the right. Above the stratum containing the prints was another layer which contained prints of an undoubted iguanodontid type.Item Fossil vertebrate tracks near Murraysburg, Cape Province(Bernard Price Institute for Palaeontological Research, 1990) McRae, Colin SThe presence of a palaeosurface with a set of relatively large concave epirelief tracks that extend for some 60 m is documented and described. The trackmaker is believed to be a member of the genus Aulacephalodon Seeley 1898 or Rhachiocephalus Seeley 1898 and to have walked across a submerged silty surface on a floodplain. A mud veneer deposited under relatively low energy conditions soon after the tracks were made, and the thermal alteration of the sediment by nearby diabase intrusives, contributed to the preservation of this set of fossil tracks.Item Gebruik van Paleontologie in Litostratigrafiese korrelasie in die Beaufort Groep, Karoo opeenvolging van Suid-Afrika [The use of palaeontology in the correlation of lithostratigraphic units in the Beaufort Group, Karoo sequence of South Africa](Bernard Price Institute for Palaeontological Research, 1990) Groenewald, Gideon HIn die Noordoos-Vrystaat is die Beaufort Groep litostratigrafies onderverdeel in 'n onderste Norrnandien Forrnasie en boonste Tarkastad Subgroep waarin twee forrnasies onderskei is. Van onder na bo is die Frankfort (sandsteen), Rooinek (sandsteen), Schoondraai (sandsteen) en Harrismith (moddersteen) Lede in die Norrnandien Forrnasie onderskei, terwyl die Verkykerskop (sandsteen) en Driekoppen (moddersteen) Forrnasies in die Tarkastad Subgroep erken is. Biostratigrafie korreleer goed met litostratigrafie en word as volg opgesom: Schoondraai Lid en onderliggende moddersteen (Dicynodon lacerticeps-Whaitsia Versamelsone); Harrismith Lid (Lystrosaurus-Thrinaxodon Versamelsone). Die Verkykerskop en Driekoppen Forrnasies het nog geen fossiele in die studiegebied opgelewer nie. Nuwe fossielvondse ( 127 eksemplare) van Dicynodon lacerticeps, Whaitsia platyceps, Prorubidgea maccabei, Lystrosaurus murrayi, Lydekkerina sp. en Rhachiocephalus magnus, in die NoordoosVrystaat, is gebruik vir die korrelasie en kartering van die Schoondraai en Harrismith Lede van die Beaufort Groep. Die Dicynodon lacerticeps-Whaitsia Versamelsone word met modderige en sanderige kronkelstrome geassosieerterwyl dieLystrosaurus-Thrinaxodon Versamelsone met droe kronkelstroom afsettings geassosieer word. . Die voorkoms van fossiele is gebruik om te bewys dat die litostratigrafiese indelings van die Beaufort Groep in die Noordoos-Vrystaat met die in die Oos-Kaap, korreleerbaar is. [In the North Eastern Orange Free State the Beaufort Group can be divided lithostratigraphically into a lower Normandien Formation and an upper Tarkastad Subgroup. Four lithostratigraphic units were recognized within the Normandien Formation, namely the Frankfort (sandstone), Rooinek (sandstone), Schoondraai (sandstone) and Harrismith (mudstone) members. The Tarkastad Subgroup is subdivided into a lower Verkykerskop Formation (sandstone) and upper Driekoppen Formation (mudstone). Biostratigraphy was found to correlate well with lithostratigraphy in the following way: Schoondraai Member and underlying mudstone (Dicynodon-Lacerticeps-Whaitsia Assemblage-zone); Harrismith Member ( Lystrosaurus-Thrinaxodon Assemblage-zone); Verkykerskop and Driekoppen Formations (barren). New discoveries (127 specimens) of Dicynodon lacerticeps, Whaitsia platyceps, Proruhidgea maccahei, Lystrosaurus murrayi, Lydekkerina sp. and Rhachiocephalus magnus , in the northeastern Orange Free State, South Africa, were used in correlating and mapping the Schoondraai and Harrismith Members of the Beaufort Group, Karoo Sequence in South Africa. Dicynodon lacerticeps-Whaitsia Assemblage-zone is associated with muddy and sandy meandering rivers while the Lystrosaurus-Thrinaxodon Assemblage-zone is associated with dry meandering river deposits. The fossil occurrences are used as proof for the correlation of the lithostratigraphic subdivisions of the Beaufort Group in the north-eastern Orange Free State with those in the Eastern Cape Province of South Africa.] ENGLISH SUMMARY Mapping of the map area 2729 (North Eastern Orange Free State, South Africa) showed that the relationship of the sedimentary history and the occurrence of vertebrate fossils within the different palaeosedimentary environments, were useful in facilitating an improved lithostratigraphic subdivision and correlation. Using 127 newly discovered vertebrate fossils for purposes of correlation, the following conclusions were arrived at: (i) Dicynodon lacerticeps and Lystrosaurus murrayi were found not to occur together, Lystrosaurus murrayi always occurring stratigraphically higher than Dicynodon lacerticeps. (ii)Rhachiocephalus mag nus is more widely distributed than was previously thought, and it is consequently eliminated as a possible marker fossil. (iii) The association of Whaitsia platyceps with Dicynodon /acerticeps indicates that the Dicynodon lacerticeps-Whaitsia Assemblage-zone extends to the northern part of the Karoo Basin. (iv) The absence of Thrinaxodon sp. fossils in this northern part of the Basin still needs to be explained. (v) The association of specific fossils with specific palaeosedimentary environments is well documented, which could be of use in correlation reasoning within the study area. (vi) Palaeontology is as much part of the sedimentary history of an area as is the smallest sedimentary structure found in mudstone or sandstone, and knowledge of, or at least interest in, palaeontology is essential in the mapping, correlation and understanding of Beaufort Group sediments.Item Morphology and growth of the Massospondylus braincase (Dinosauria Prosauropoda)(Bernard Price Institute for Palaeontological Research, 1990) Gow, Chris EThe almost complete disarticulated braincase of a young Massospondylus, and the partial braincase of a very large individual in which the laterosphenoid bones are preserved, are described.Item A new vertebrate biozone at the base of the Beaufort Group, Karoo sequence (South Africa)(Bernard Price Institute for Palaeontological Research, 1990) Rubidge, Bruce SA new vertebrate biozone at the base of the Beaufort Group has been identified. This biozone is the oldest vertebrate biozone of the Beaufort Group and contains fossils of various therapsid genera which are more primitive than previously known related forms from the Karoo. The name Eodicynodon - Tapinocaninus Assemblage Zone is proposed as these two genera of therapsid are the most plentiful from this biozone and have not been found in the rocks of the overlying Dinocephalia Assemblage (Tapinocephalus) Zone.Item Physiological implications of the bone histology of Syntarsus rhodesiensis (Saurischia: Theropoda)(Bernard Price Institute for Palaeontological Research, 1990) Chinsamy, AnusuyaFemora of Syntarsus rhodesiensis specimens of differing ontogenetic stages were sectioned and prepared for histological study. Features such as the structure of the cortical bone tissue, the degree of vascularisation and haversian substitution, and the general pattern of bone deposition through ontogeny, are described. The question of the bearing of bone histology on interpretation of the probable physiology of Syntarsus is also discussed.Item Skulls of the prosauropod dinosaur Massospondylus carinatus Owen in the collections of the Bernard Price Institute for Palaeontological Research(Bernard Price Institute for Palaeontological Research, 1990) Gow, Chris E; Kitching, James W; Raath, Michael ADescription of the skull of Massospondylus (Prosauropoda, Anchisauridae) is largely unnecessary since excellent descriptions now exist of Plateosaurus (Galton 1984, 1985a) which, though larger and of slightly different proportions, is anatomically almost identical. This paper presents comprehensive illustrations of the Massospondylus skulls in the Bernard Price Institute collections and discusses only those aspects of this material in which Massospondylus differs from Plateosaurus, or which further add to our knowledge of the prosauropod skull. It is shown that Attridge et al. ( 1985) give spurious reasons for considering the recently discovered Massospondylus skull from Arizona to differ from the southern African taxon, and that the suggestion of Crompton and Attridge ( 1986) that this animal may have had a horny beak on the tip of the lower jaw is unnecessary and improbable.Item A tribute to James William Kitching(Bernard Price Institute for Palaeontological Research, 1990) Raath, Michael A