3. Electronic Theses and Dissertations (ETDs) - All submissions
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Item Middle Permian diversity of large herbivores: taxonomic revision of the titanosuchidae (therapsida, dinocephalia) of the Karoo basin, South Africa(2022) Jirah, SifelaniTitanosuchidae are a goup of derived herbivorous long snouted dinocephalians currently only known from the South African Karoo Supergroup. Taxonomic revision of the titanosuchids, for the first time accompanied by detailed anatomical descriptions and illustrations of representative cranial and postcranial material, enabled recognition of only two genera each represented by a single species out of nine previously recognized species. These are Titanosuchus ferox and Jonkeria truculenta. Jonkeria vanderbyli, Jonkeria ingens, Jonkeria haughtoni, Jonkeria parva, Jonkeria rossouwi and Jonkeria boonstrai are here, synonymized with Jonkeria truculenta. The species Jonkeria koupensis is a nomen dubium only identified as Titanosuchid indet. Cranial characters, which modify during ontogenetic development, were, recognized for Jonkeria, and for the first time an ontogenetic growth series is, presented for this species. This research has for the first time produced a phylogenetic analysis of the two titanosuchid taxa with their deuterosaurid, estemmenosuchid, anteosaurid, styracocephalid and tapinocephalid counterparts confirming the sister group relationship between Styracocephalidae, Estemmenosuchidae, Titanosuchidae and Tapinocephalidae. This phylogenetic analysis manifests a long ghost lineage extending over most of the Guadalupian. The first extensive stratigraphic analysis of the Titanosuchidae shows that the South African Karoo Supergroup hosts both genera in the upper levels of the Abrahamskraal Formation (Moordenaars Member) with a single specimen (Titanosuchid indet) recovered in the lower levels of the overlying Poortjie Member of the Teekloof Formation. The absence of titanosuchids in the Karelskraal Member of the Abrahamskraal Formation and their reappearance in the lower Poortjie could be a case of a “Lazarus taxon”. This gap in the stratigraphic range of this taxon iv (range gap), as well as the long ghost lineage, will hopefully be filled in future by intensive targeted collecting in the relevant stratigraphic intervals.Item Stratigraphy and sedimentology of the middle Permian Abrahamskraal formation (Tapinocephalus Assemblage Zone) in the southern Karoo around Merweville, South Africa.(2014-02-07) Jirah, SifelaniA study of the Abrahamskraal Formation in the area around Merweville, in the southwestern corner of the Karoo Basin has revealed the presence of traceable lithological units with lateral continuity throughout the study area. The stratigraphic section measured in this part of the basin matches the section measured by Jordaan, (1990) south of Leeu Gamka, with a basal arenaceous unit overlain by a predominantly argillaceous succession. The thickness of the Abrahamskraal Formation in this part of the Karoo Basin in 2565m, charactersized by a braided depositional environment in the lower 2075m and a meandering depositional environment in the upper 490m. Biostratigraphically the succession comprises a basal Eodicynodon Assemblage Zone which constitutes the lower 1104m and this is overlain by a 1461m thick Tapinocephalus Assemblage Zone whose upper limit is 21m below the Poortjie Member of the Teekloof Formation. This study has also corroborated the work by earlier authors who proposed a northeasterly palaeoflow direction as well as contributing to the global correlation of the Middle Permian terrestrial tetrapod faunas where the Eodicynodon Assemblage Zone correlates with the fauna from the Russian Ocher & Ischeevo; fauna of China’s Xidagou Formation and Rio da Rosto fauna of Brazil while the Tapinocephalus Assemblage Zone fauna corrletaes with fauna from Mezen and Ischeevo in Russia, Posto Queimado fauna in Brazil and those from the Madumabisa strata of Zimbabwe.