Browsing by Author "Smith, Roger"

Now showing 1 - 7 of 7
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    Cold case files : palaeoforensic and taphonomic study of the Mamafura dicynodont from the end permian
    (2010) Fordyce, Nicholas; Chinsamy-Turan, Anusuya; Smith, Roger
    Dicynodonts were non-mammalian herbivorous therapsids (mammal-like reptiles) that flourished world-wide during the Permian and Triassic Periods. They are nowhere more abundant than in the rock strata of the Karoo basin in South Afiica. Taphonomy, the transition from biosphere to lithosphere, is of great geological and biological significance and has provided remarkable insight into palaeoenvironments. A partially articulated dicynodont that has been fossilised alongside an unidentified predator tooth shows evidence of predation and is analysed here. The dicynodont is possibly Oudenodon grandis and was most likely drowned after which it was scavenged from by a gorgonopsian predator, Aelurognathus. The fossil is important as it provides further insight into the ecology of the Late Permian and it enhances our taphonomic understanding.
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    Dinosaur breeding grounds in Patagonia
    (2012) Smith, Roger
    Prompted by the recent publicity around dinosaur eggs and embryos having been found in South Africa, Dr Roger Smith was invited to join an expedition to South America to follow up on the discovery of 'the world's largest dinosaur' in Patagonia. This podcast will be of interest to Paleontology students and members of the public interested in dinosaurs.
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    Evidence of a therapsid scavenger in the Late Permian Karoo Basin, South Africa
    (2012) Fordyce, Nicholas; Smith, Roger; Chinsamy, Anusuya
    Dicynodonts are an extinct group of herbivorous non-mammalian therapsids (‘mammal-like’ reptiles) that are widely known from terrestrial Permo-Triassic strata throughout Pangaea. Dicynodont fossil remains are common within the Late Permian Beaufort Group of the Karoo Basin in South Africa. A large, partially articulated dicynodont skeleton recovered from the Tropidostoma Assemblage Zone is taphonomically important in having an unusual disarticulation pattern, bone surface punctures and a broken tooth of an unidentified carnivore associated with it. Here we report on the nature of the bone damage, and the identity of the carnivore that lost a canine tooth whilst scavenging the dicynodont carcass. The morphological characteristics of the serrations on the unidentified tooth were compared with those of contemporaneous carnivores, the gorgonopsians and therocephalians. Scanning electron microscopy analysis of a silicone cast of the unidentified tooth revealed distinctive 0.5-mm square-shaped serrations. Our comparative assessment of the tooth size, curvature, cross-sectional shape and morphology of the serrations revealed that the unidentified canine most closely matched Aelurognathus, a gorgonopsian known from the same assemblage zone.
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    Extinctions: Past and Present Week 3 - Reading rocks
    (2017-03-17) Chinsamy-Turan, Anusuya; Smith, Roger
    In this video, Professor Anusaya Chinsamy-Turan interviews Dr Roger Smith about his 30-year career working on fossils in the Karoo basin of South Africa. He outlines the research questions he has investigated, the scientific techniques he has used, and the interesting findings he has uncovered. This is video 3 in Week 3 of the Extinctions: Past and Present MOOC.
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    Life after extinction: palaeoenvironments of the earliest Triassic lower Katberg formation, including the origin of Lystrosaurus Bonebeds from the Karoo Basin, South Africa
    (2012) Viglietti, Pia A; Smith, Roger; Compton, John
    This study argues for the formation of bonebeds by aggregation of sub-adult Lystrosaurus during extended episodic periods of extreme climatic conditions, such as cold or drought, in the earliest Triassic Karoo Basin.
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    Sedimentology and taphonomy of cenozoic vertebrates from Langebaanweg, Cape West Coast, South Africa; with palaeoecological interpretations
    (2017) Cohen, Brigette Fiona; Stynder, Deano D; Smith, Roger
    The fossil locality Langebaanweg, is world renowned for its vast abundance and diversity of fauna. Langebaanweg is the only fossil site in South Africa that preserves remains from the Late Miocene to Early Pliocene. The Mio-Pliocene is a period of major climatic change, with global temperatures falling, and increased aridity and seasonality across the African continent. Langebaanweg, located on the coastal platform of Southern Africa, is ideally placed to investigate how these major changes in climatic conditions in the Mio-Pliocene affected ecology, environment and animals in south-western Africa. The majority of fossils from Langebaanweg were recovered from the early Pliocene Varswater Formation. Specifically, the two major fossil bearing horizons, the Langeberg Quartz Sand Member (LQSM) and the overlying Muishond Fontein Pelletal Phophorite Member (MPPM). The Varswater Formation has been reconstructed as a fluvio-estuarine environment with localised tidal-flats and marshes. The relationship between the MPPM and the LQSM and their relative ages and depositional environments is controversial. This thesis sought to investigate the depositional environment of the MPPM and LQSM in Langebaanweg E-Quarry, with the aim of identifying the relationship and comparative ages of the two members. In order to investigate this, three test pits were excavated at Langebaanweg and the lithology, sedimentology and taphonomy of remains recovered from the test pits was studied. The test pits were located in the sivathere bonebed, the 1976/2 excavation and in a new locality positioned 200 m to the south of the 1976/2 excavation. The depositional environment of the bonebed and 1976/2 were investigated as well as their relationship to each other. The taphonomic pathways by which bones came to be interred in each test pit was identified. Sedimentologically, the MPPM and LQSM were found to be almost identical and the only major distinguishing characteristic was the lack of phosphate in the latter deposit. This indicates that the two horizons were deposited in the same setting and/or by the same depositional process. Additionally the MPPM and LQSM sediments were dominated by fine to very fine sand grains and muds and silts were virtually absent (except in the MPPM in one test pit). This, together with the texture of the sediments, lead to the conclusion that the MPPM and LQSM, in Langebaanweg EQuarry, had a marine origin. Langebaanweg E-Quarry is here interpreted as a barrier-island estuary formed on a wave-dominated coast. Given the consistency of sediments, taxa and taphonomic characters between the MPPM and the LQSM they are interpreted as representing a single unit or depositional event where the upper parts (MPPM) have been secondarily phosphatised. Under this scenario, there is no unconformity or age gap between the MPPM and the LQSM. Investigations of the depositional environment of the 1976/2 excavation concur with Hendey's (1980) reconstructions for a river channel. The results of this study reject previous reconstructions of the sivathere bonebed as a lag deposit of a river channel (Roberts et al. 2011; Smith & Haarhoff 2006). This study shows that the bonebed was deposited in a low energy freshwater pool associated with the river. No evidence was found for an aquifer-fed spring as suggested by Brumfitt et al. (2013). The MPPM sediments of the test pit located to the south of 1976/2 displayed a dominance of fine muds and silts with a possible high organic content. This was interpreted as a possible marsh habitat. This is the first study to identify a marsh environment at Langebaanweg since the 1980's and all other examples of this type of environment have been destroyed by mining. The identification of this locality will provide exciting new opportunities for future research. Taphonomic analysis has shown that the influence of fire and predation on faunal remains excavated in this study was small and internment in all cases was quick. As a final note, this thesis conducted a review of previous research and excavations at Langebaanweg E-Quarry by Dr Brett Hendey and identified the location of some fossil collecting localities that had been lost. These were plotted onto aerial photographs, which will be beneficial to future researchers trying to identify old locals or identify new deposits.
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    The palaeobiology of the late Permian dicynodont Endothiodon (Therapsida, Anomodontia)
    (2022) Maharaj, Iyra Esmen Maeve; Chinsamy-Turan, Anusuya; Smith, Roger
    Among the dicynodonts, the late Permian genus Endothiodon is unique for its cranial morphology and unusual dentition. Despite the extensive amount of Endothiodon cranial material recovered from Gondwanan deposits worldwide, there is much that is unknown about its palaeobiology. This thesis provides fresh insights into the taxonomy, dental histology and postural reconstructions of Endothiodon based on the crania and postcrania of the taxon. Despite a few interventions over the years, the taxonomy of the genus Endothiodon has been in a stateof confusion since the late 19th century. While an abundance of cranial material from various Gondwanan deposits has added insights into intrageneric variation, a formal taxonomic review of the genus and species therein has never been conducted and thus remains unresolved. A sample of 131 Endothiodon skull specimens were examined to assess anatomical variation,and 24 taxonomically relevant characters were determined and scored in a phylogenetic analysis. The results suggest that only three Endothiodon species are valid: E. bathystoma, E. mahalanobisi, and E. tolani. The presence of E. mahalanobisi is evidenced in east Africa as well as India for the first time. In combination with micro-computed tomographic (µ-CT) scanning, a new approach of transversely sectioning each jaw at multiple levels of depth was employed, allowing the dental and alveolar bone microstructureto be described at varying depths in the jaw. The results show that South African E. bathystoma had a soft tissue attachment, and its tooth eruption sequence agrees with the Zahnreihen mode of tooth replacement, where teeth drift from the lingual margin labially, where they are eventually resorbed. This investigation also shows histologically that the teeth from the single-rowed maxillae are replaced less frequently than that of multi-rowed dentaries. Although some postcrania of Endothiodon have been recovered in recent years from the Karoo Basin ofSouth Africa and from the K5 Formation of Mozambique, to date no studies of the functional morphology of the postcranial skeleton have been conducted. Three-dimensional models of forelimb and hindlimb elements were used in digital articulation, showing that mobility in the forelimb was more restricted than that of the hindlimb. The results also show that the stationary posture of Endothiodon follows that of other dicynodonts, whereby the hindlimb is held higher off the ground than the forelimb. Overall, this thesis has unravelled the taxonomy of Endothiodon, provided novel information regarding its complex dental histology and tooth replacement patterns in both the maxillae and dentaries, and has permitted a concise assessment of its posture.