Volume 18 1975
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Item Palaeontologia africana Volume 18(Bernard Price Institute for Palaeontological Research, 1975)Item Planktonic foraminifera and calcareous nannofossils at the Cretaceous-Tertiary contact in Zululand(Bernard Price Institute for Palaeontological Research, 1975) Stapleton, R PAssemblages of planktonic foraminifera and calcareous nannofossils for the Maestrichtian and Danian of Zululand are listed and illustrated. The Globotruncana gansseri and G. mayorensis foraminiferal zones are present in the Maestrichtian. The Globigerina triloculinoides and Globorotalia compressa foraminiferal subzones are present in the Danian. The Maestrichtian in this area cannot be subdivided on the basis of calcareous nannofossils. Danian nannofossil zones present are those of Cruciplacolithus tenuis and Chiasmolithus danicus . The Cretaceous-Tertiary faunal extinctions are briefly discussed and it is concluded that lowered temperatures were a factor in this extinction.Item A problematical element in the Glossopteris flora of Vereeniging(Bernard Price Institute for Palaeontological Research, 1975) LeRoux, S FAn unusual element, not previously recorded from the mixed Glossopteris Flora of Vereeniging, is described here. The type material was obtained from a rich fossiliferous zone, previously described by the author (Le Roux, 1963, pp. 1-2). The material available for study consists of a single specimen of an incomplete frond preserved in the form of an impression in fine-grained laminated clay.Item Trace fossils in the Ecca of northern Natal and their palaeoenviromental significance(Bernard Price Institute for Palaeontological Research, 1975) Hobday, D K; Tavener-Smith, RBecause of the rarity of body fossils in the Ecca Group fossil burrows, tracks and trails are of potential value in supplementing primary sedimentary evidence concerning the palaeoenvironmental factors of bathymetry, energy level and food supply. The three most important ichnogenera are Skolithos, Corophioides and Scolicia. The first two are restricted to the upper portions or Middle Ecca upward-coarsening regressive cycles attributed to delta progradation. They arc representatives of Seilacher's (1967) Skolithos and Glossijungites communities, indicating shallow water conditions with diastems. Scolicia occurs at lower levels in the cycles and corresponds to Seilacher's deeper water Cruziana community. Meandering trails Helminthopsis and Taphrhelminthopsis in the Lower Ecca belong to Seilacher's deep water Nereites community. Less common ichnogenera include the U-burrows Diplocraterion and Rhizocorallium. It has proved impossible positivelv to identify many trace fossils such as short ramifying burrows, chevron trails, dumbbell-shaped surface impressions, digitate tracks and problematic elliptical casts. Trace fossils have not been recognised with certainty in the fluviatile deposits which comprise the bulk or the coal-bearing strata of northern Natal.Item The morphology and relationships of Youngina capensis Broom and Prolacerta broomi Parrington(Bernard Price Institute for Palaeontological Research, 1975) Gow, Chris EComprehensive descriptions of the osteology of Youngina capensis Broom and Prolacerta broomi Parrington are presented. New details of the braincase of Proterosuchus fergusi Broom are given as these became necessary for comparative purposes. It is suggested that the initial radiation of sauropsid reptiles was a Permian event as yet poorly documented. The phylogenetic position of Youngina forward and backward in time cannot be narrowly defined, though certain characters seem specifically to preclude it from lizard ancestry. Prolacerta, on the basis of tooth implantation, braincase morphology and postcranial anatomy is shown to be closest to the proterosuchian thecodonts. It is very definitely not concerned with lizard origins, but would on available evidence seem to be a perfectly good ancestor for the middle Triassic forms Macrocnemus and Tanystropheus which latter must cease to be regarded as lizard ancestors. We have here a rather distinct reptilian lineage which branched off from common ancestral stock just prior to the advent of archosaurs.Item Palyno-stratigraphy of the lower Karroo sequence in the central Sebungwe District, Mid-Zambezi Basin, Rhodesia(Bernard Price Institute for Palaeontological Research, 1975) Falcon, Rosemary SHart (1962) was the first to discuss seriously the subject "palynology-key to stratigraphy" with regard to Southern Africa. Since then a number of publications have appeared on African Karroo palynology. However, to date only one large scale microfloral zonation scheme has been proposed -that of Hart (1967). In this, four major palynofloristic zones were outlined for Lower Karroo (Permian) sequences, drawn from surface and sub-surface material in South and Central Africa. Another scheme, dividing the Permian into eight zones in S. Africa (Great Karroo Basin) , is as yet unpublished (Anderson, in press). In an attempt to apply palynology to the problems of geological correlation and relative age determinations, specifically in the field of coal exploration in Rhodesia, a standard section in the form of one borehole, the Matabola Flats borehole, well-sited, deep and with apparently continuous deposition was chosen for palynological biostratigraphic analysis. Fifty-five miospore genera and ninety-eight species have been recognised in this study. Their systematic descriptions and statistical analyses are published elsewhere, Falcon 1975 a, b. Detailed analysis of the forty-eight productive samples show large scale micro-floral changes up the stratigraphic column. Four major assemblage zones and eight assemblage sub-zones are herein proposed, thereby expanding by four the palynofloristic zones of Hart.Item The skeleton of the Triassic anomodont Kannemeyeria wilsoni Broom(Bernard Price Institute for Palaeontological Research, 1975) Cruickshank, Arthur R IThe general structure of the post-cranial skeleton of many Triassic anomodonts is now well known, but in Africa that of the stratigraphically important Lower Triassic (? Scythian) genus Kannemeyeria is known only from dissociated elements. A brief description is given for the first time of an almost complete skeleton ascribed to this genus. The environment of deposition is described briefly. The locality of the type species of the genus is also noted .Item The affinities of Proterochampsa barrioneuvoi Reig(Bernard Price Institute for Palaeontological Research, 1975) Cruickshank, Arthur R IProterochampsa barrioneuvoi Reig is re-examined and is confirmed as a proterosuchian thecodont. None of the features previously thought to ally it to the Crocodilia are solely characteristic of that group. On the other hand it is not a phytosaur nor phytosaur ancestor, only showing one real trend towards these animals in the rearward migration of the internal and external nares. Proterochampsa and its relatives Chanaresuchus, Gualosuchus and Cerritosaurus are too late in time to be phytosaur ancestors. They are grouped together in the Proterochampsidae, a family within the Proterosuchia.Item Further consideration of the capitosaurids from the Upper Luangwa Valley, Zambia(Bernard Price Institute for Palaeontological Research, 1975) Chernin, Susan; Cosgriff, J WItem Permo-Triassic "lizards" from the Karroo(Bernard Price Institute for Palaeontological Research, 1975) Carroll, Robert LThree genera of sauropsid reptiles from the Permo-Triassic beds of South Africa - Saurosternon Huxley, Paliguana Broom and Palaegama Broom - were originally described as lizards, or the immediate ancestors of that group. Restudy of these forms confirms that they are close to the ancestry of later Mesozoic and Cenozoic squamates. The skull is somewhat primitive, but in size, proportions and function extremely similar to that of Kuehneosaurus. The pectoral girdle is lacertoid in the proportions and orientation of the clavicles and interclavicle; the anterior margin of the scapulocoracoid is fenestrate, and the articulating surface of the glenoid is very short. A sternum is present and one specimen shows ventral connections between the ribs and the sternum. In Saurosternon, the forelimb can be seen as very similar to that of living lizards, with special epiphyseal articulating surfaces on the proximal end of the humerus and distal end of the ulna. The pelvic girdle remains primitive, but the rear limb is close to the pattern in lizards. The fifth metatarsal is not obviously hooked, and all five distal tarsals are retained, but the proportions and functions of the ankle presage the condition in living lizards. Epidermal scales are present. Following Romer, these forms are all included in the Family Paliguanidae. They are placed in the Suborder Lacertilia, provisionally in the Infraorder Eolacertilia.