Browsing Volume 31 1994 by Issue Date
Now showing 1 - 8 of 8
Results Per Page
ItemPermian palynomorphs from the number 5 seam, Ecca Group, Witbank/Highveld coalfields, South Africa(Bernard Price Institute for Palaeontological Research, 1994) Aitken, G AA palynological study of the number 5 seam in the Ecca group has yielded a wide variety of miospores, with a lateral and vertical consistency in their relative abundance, diversity and composition. Striate bisaccate pollen genera predominate, particularly Protohaploxypinus Samoilovich emend. Morbey 1975, Striatopodocarpites Zoricheva & Sedova ex Sedova emend. Hart 1964 and Weylandites Bharadwaj & Srivastava 1969. On a regional scale the number 5 seam palynomorphs correlate both quantitatively and qualitatively with Biozone F of MacRae (1988) from the Waterberg and Pafuri coal-bearing basins, and Hammanskraal plant locality. Broad palaeoenvironmental inferences drawn from both the palynology and sedimentology of this seam, support a flood plain setting, comprising shallow wide open pans and peat swamps interspersed with wide water-logged mud flats . The surrounding highlands would have been forested mostly by plants adapted to wind dispersal with colonisation of the levees and margins of smaIl ponds by spore producers. The age of the number 5 seam is tentatively suggested as Guadalupian, which in turn is equated with the Tatarian (European Standard usage); Midian to Dzhulfian (Tethys usage). ItemNew antelope fossils from Awash, Ethiopia, and phylogenetic analysis of Hippotragini (Bovidae, Mammalia)(Bernard Price Institute for Palaeontological Research, 1994) Vrba, Elizabeth S; Gatesy, JohnNew hippotragine antelope fossils from the Middle Awash, Ethiopia, include a new species Praedamalis howelli from Maka, an early species of Oryx from Matabaietu, and Hippotragus gigas from Gamedah. Our comparisons of these fossils with all other known fossil and Recent Hippotragini includes a cladistic analysis. The results suggest that the two major lineages in the monophyletic Hippotragini are Hippotragus including taxa from the Siwaliks previously ascribed to Sivatragus, and a Praedamalis - Oryx sister-group. Some evolutionary and biogeographic implications of the new fossils from the Middle A wash deposits are discussed. ItemA new find of Trematosuchus (Amphibia, Temnospondyli) from the Cynognathus Zone of South Africa(Bernard Price Institute for Palaeontological Research, 1994) Shishkin, Michael A; Welman, JohannSome aspects of the cranial morphology of Trematosuchus sobeyi, a temnospondylous Trematosaurid amphibian from the South African Cynognathus Zone, are described in detail for the first time from a new fossil find referred to this form. The new specimen is similar in size to that of the holotype of Trematosuchus sobeyi but differs in the more moderate elongation of the snout. Apart from the presence of the septomaxilla, the validity of the genus Trematosuchus is reconfirmed inter alia by its much larger size and the position of the supraorbital sensory groove alongside the lachrymal margin rather than crossing this bone. This last characteristic differentiates Trematosuchus from all other trematosauroids. T. Sobeyi is of particular importance since it represents the only purely freshwater Gondwanan form closely comparable to the European Trematosaurus. The presence of T. Sobeyi in the lowermost strata of the Cynognathus Zone in South Africa, in association with some other forms related to the Upper Olenekian (Middle Buntsandstein) tetrapod assemblage of Europe, indicates that these strata belong to the Scythian in contrast to the higher strata of the Cynognathus Zone which are Anisian. ItemCatalogue of fossil sites at the Buxton Limeworks, Taung(Bernard Price Institute for Palaeontological Research, 1994) McKee, Jeffrey KThe Buxton Limeworks, in the Taung district at the southeastern margin of the Kalahari Desert, harbours fossil deposits in the calcareous tufas spanning a time period from the late Pliocene to the present. Many such fossil sites, including the type site of Australopithecus africanus, have been exposed by quarrying and noted by various researchers since 1919. As many of the site locations have been lost in the past due to inadequate records and continued quarrying, an effort was made to relocate previously known sites and to discover new sites. There are now 17 preserved and recognized fossil sites in the Buxton Limeworks, the location and nature of which are documented here for future researchers. ItemNew find of Diarthrognathus (Therapsida: Cynodontia) after seventy years(Bernard Price Institute for Palaeontological Research, 1994) Gow, Chris EDiarthrognathus is arguably South Africa's most famous therapsid fossil. Since its discovery seventy years ago no new material had come to light until now. This paper records the recovery, from the Elliot Formation of South Africa, of a partial left lower dentary with most of its dentition preserved. ItemFossil wood of Cretaceous age from the Namaqualand continental shelf, South Africa(Bernard Price Institute for Palaeontological Research, 1994) Bamford, Marion K; Corbett, Ian BFossil wood was collected from sediments on the Namaqualand shelf, West Coast, South Africa, between the Orange River mouth and just to the south of Kleinzee. Forty three of these samples are here described. All the woods are gymnospermous and have abietinian tracheid pitting. Nineteen of them are well enough preserved to be identified to species level: Podocarpoxylon cf. umzambense, Mesembrioxylon cf. stokesii, M. cf. sahnii, M. cf. woburnense and Protocupressinoxylon cf. purbeckensis. The remainder of the woods have been placed in the artificial genus Mesembrioxylon without species names. The woods are probably primitive members of the Podocarpaceae growing during the Lower Cretaceous. They indicate a seasonal climate and inhabited the extensive low-lying coastal regions. ItemThe phylogeny of basal archosaurs(Bernard Price Institute for Palaeontological Research, 1994) Juul, LarsArchosaur systematics has received much attention from the mid 1970s and several influential works on this topic have emerged. As discrepancy exists among proposed phylogenies, some of the most important of the papers in question are assessed here. Characters used in cladistic analysis have often been selected too uncritically or phrased too vaguely to be of diagnostic value, and previously used, seemingly valid apomorphies have been disregarded by later workers, sometimes for no apparent reason. In the present paper a character matrix for the Archosauria was assembled by critically incorporating, and often modifying, characters used in earlier works on archosaur systematics. A phylogeny resulting from cladistic analysis of the matrix compiled here supports the monophyly of Archosauria, Crown-group Archosauria Crurotarsi, Ornithodira, Dinosauromorpha and Dinosauria, and disputes the existence of Suchia less Ornithosuchidae and of a monophyletic Crocodylotarsi. A new taxon, Dromaeosuchia, is erected for a clade consisting of Ornithosuchidae, Crocodylomorpha and Gracilisuchus plus Postosuchus.