A comprehensive re-assessment of the South African ovuliferous glossopterid fructifications was conducted. This involved the creation of a database of quantitative and descriptive information based on over 500 specimens from 14 localities in the northern and eastern Karoo Basin and the Bushveld Basin. Specimens belonging to four families, thirteen genera and 24 species were measured in detail, re-described, re-evaluated and in many cases, existing diagnoses were emended. In total, this revision effected the creation of four new genera, one new species and emendations to two families, seven genera and thirteen species. All taxa were photographed, and representative specimens were drawn and reconstructed. An illustrated key to the ovuliferous glossopterid fructifications was compiled as a guide to the identification of all known species from South Africa. The South African literature on glossopterid polysperms was reviewed, with reference to discoveries from other parts of Gondwana. All the glossopterid ovuliferous fructifications examined were impression fossils, and a major component of the project was to re-evaluate the structure and morphology of the specimens from a taphonomic perspective. Although not widely taken into account in palaeobotanical studies, impression fossils are essentially moulds of the original plant, providing valuable three-dimensional information which is easily overlooked. This approach led to the discovery of several radical, new morphological types in well-known taxa. These discoveries could change the way glossopterid homologies are interpreted in the future. Additionally, these structures may help to resolve some of the conflicting reports regarding the presence of more than one set of cuticle per fructification, and sterile scales. Hirsutum intermittens was found to have a peculiar dual wing structure, and was transferred to a new genus, Bifariala. In addition to the primary wing with its tapered base, extended apex and apically inclined striations, an additional, secondary wing was recognised in these fructifications, which has a structure similar to that of Scutum and Gladiopomum. Hirsutum leslii was found to possess a unique, hood-like wing which arched over the seed-bearing surface iv of the fructification, partially enclosing the ovules, which were in many cases found still attached to the fructification. The species was deemed to be a junior synonym of Elatra. The semi-enclosed structure of Elatra raised questions regarding the pollination and seed dispersal mechanisms employed by members of this genus. A review of the literature on Arberia, and examination of South African specimens, led to emendation of the genus to include the presence of a scalelike extension distal to the single seed attachment point at ultimate branch termini. Appreciation of the bifacial nature of some Arberia species, which bear lateral branches across one surface of a laminate primary axis has important implications for the recognition of homologies and establishment of evolutionary trends among members of the glossopterids. Existing ideas regarding the homologies and phylogeny of the glossopterids were refined and developed further. The glossopterid polysperms are considered to have evolved from a basal member of the Arberiaceae, with planation, fusion and reduction of lateral branches having given rise to fructifications of the Rigbyaceae and Dictyopteridiaceae. Members of the Lidgettoniaceae are thought to have been derived from members of the Dictyopteridiaceae. The hypothesised derivation of the glossopterid fertile structures from modified shoots rather than leaves, supports an affiliation with the cordaitaleans rather than the pteridosperms. The biostratigraphic and biogeographical significance and application of the South African genera of glossopterid polysperms was briefly evaluated.

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Windblown dust is a significant source of sediment and organic matter for many basins, but its influence on ancient basins can be difficult to detect and quantify. We quantified the biomarker content, including n-alkanes, hopanes, and steranes of the Brushy Canyon Formation sandstones and siltstones to evaluate the significance of windblown dust in delivery of sediment and terrestrial organic matter to the Middle Permian Delaware Basin. Ramp siltstones of the basin have been interpreted as representing deposits of unconfined low-density turbidity currents or "aeolo-marine" sediments. We analyzed the organic contents of five samples of channel-confined turbiditic sandstones and siltstones and five samples of ramp siltstones outcropping in the Guadalupe Mountains National Park, West Texas, to estimate the relative proportions of terrestrial and marine organic matter in the two types of host rocks. The total organic carbon content of all samples varied from 0.07 percent - 2.04 percent. The abundance of high molecular weight n-alkanes (n-C27 and greater) suggests that terrestrial organic matter was present in nearly all samples. Terrestrial organic matter input to the basin was characterized using a crossplot of pristane/n-C17 versus phytane/n-C18. Ramp siltstones showed ~10-fold greater variation in terrestrial content than did turbiditic sandstones and siltstones. This observation is more consistent with the aeolo-marine interpretation of ramp siltstones, and suggests that terrestrial organic matter was delivered to the Delaware Basin by wind transport during deposition of the Brushy Canyon Formation.

The parareptilian group Procolophonoidea has been increasingly studied in recent years, and a high survival rate during the P/Tr extinction event has been estimated tor the ciade. Procolophonoid interrelationships, however, remain poorly known. Here, descriptions of the procolophonids Anomoiodon liliensterni and Leptopleuron lacertinum, and the possible Permian Russian procolophonoids, are provided. Anomoiodon and the genus Kapes were found to be closely related but there is not enough evidence to support the synonymy of the two genera. Leptopleuron is described in great detail, making it one of the most completely knovm procolophonoids. Of the possible Permian Russian procolophonoids, Suchonosaurus minimus was found to be a member of the more inclusive Procolophonidae, whereas Microphon exiguus and Kinelia broomi fall outside of Procolophonoidea. Nyctiphruretus acudens might be the sister taxon of Procolophonoidea but an alternative hypothesis of Nyctiphruretus being more closely related to pareiasaurs and nycteroleterids also received support, A phylogenetic study. including 39 procolophonoid taxa, was conducted. The results suggest novel compositions of the procolophonid clades Leptopleuroninae and Procolopphoninae; the monophyly of the genus Kapes was questioned; the phylogenetic position of Suchonosaurus, Pintosaurus and Phaantosaurus among the other basal procolophonids remains unresolved; and the results cast doubt on Procolophonoidea being divided into the clades Owenettidae and Procolophonidae. The topology with the best stratigraphic fit indicates that only 57% of procolophonoid lineages might have survived through the P/Tr boundary. However, it is also possible that up to 80% lineages crossed the boundary but this requires a scenario that maximizes the number of ghost lineages. A stratigraphical analysis supports separate Owenettidae and Procolophonidae.

No description available.

No description available.

Call number: LD2668 .T4 1950 C63 / Master of Science

No description available.

No description available.

Tangasaurid eosuchians are represented by hundreds of specimens from the Permo-Triassic strata of Madagascar and Africa. The confusion surrounding the identification and anatomy of these reptiles is resolved by comparative anatomy and relative measurements, and three genera, Thadeosaurus, Tangasaurus and Hovasaurus, are described. Extensive growth series present a unique opportunity to study differences in growth strategies in two closely related Permian genera, one that was terrestrial (Thadeosaurus) and the other aquatic (Hovasaurus). The vertebrae of Youngina have a derived character state that indicates close relationship with the tangasaurids. A new genus and species of eosuchian, Acerosodontosaurus piveteaui, has a specialized feature in the carpus that is found in the Tangasauridae. The relationships between tangasaurids and other eosuchians are considered.