- Title
- Pleistocene vertebrate trace fossils from the Cape south coast of South Africa: inferences and implications
- Creator
- Helm, Charles William
- Subject
- Geology, Stratigraphic -- Pleistocene
- Subject
- Vertebrates, Fossil -- South Africa
- Subject
- Paleontology -- Pleistocene
- Date Issued
- 2023-04
- Date
- 2023-04
- Type
- Doctor's theses
- Type
- text
- Identifier
- http://hdl.handle.net/10948/60589
- Identifier
- vital:65942
- Description
- Palaeoichnology, the study of fossil tracks and traces, has had a relatively late start on the Cape south coast of South Africa. Since its inception in 2007 the Cape south coast ichnology project has led to the identification of 326 Pleistocene vertebrate ichnosites in aeolianites (cemented dunes) and cemented foreshore deposits between the community of Arniston in the west and the Robberg Peninsula in the east, a distance of approximately 350 kilometres. As a result, significant palaeoevironmental, palaeocological and palaeoanthropological inferences have been made. This thesis brings together this corpus of work, and attempts to answer the question of how ichnology can inform the understanding of the Cape south coast Pleistocene environment, and how the trace fossil record can complement the body fossil record. Achieving this objective involves the development of a definitive regional account. This includes descriptions of the regional geological context, Quaternary sea-level changes, and the state of knowledge of the region’s Pleistocene palaeoenvironment, palaeoanthropology, and body fossil record, along with an understanding of the roles of substrate and taphonomy in regional ichnology. A discussion of geochronology includes the age results from specimens submitted for dating through optically stimulated luminescence – dated deposits range in age from Marine Isotope Stage 11 through Marine Isotope Srage 3. The body of the thesis is formed by systematic descriptions of the vertebrate ichnosites, accompanied by interpretation and comments. Three databases have been compiled: ichnosites, photographs, and photogrammetry images. In synthesizing this data, four underlying questions are addressed: what is the global relevance of the Cape south coast ichnosites, how can these studies complement the vertebrate body fossil record, how can they contribute to the understanding of Pleistocene palaeoenvironments and palaeocology, and how can they contribute to palaeoanthropology? The Cape south coast is of global ichnological importance. Unanticipated findings which augment the sparse reptilian body fossil record include tracks and traces of crocodiles, monitor lizards, very large tortoises (the first of their kind in the global record), and hatchling sea turtles. Two new ichnogenera have been erected to describe the sea turtle tracks, each containing a new ichnospecies: ustralochelichnus agulhasii and Marinerichnus latus. Avian ichnosites are the oldest in southern v Africa, and include the presence of tracks of larger-than-expected birds, which may represent large chronosubspecies or may suggest the possibility of extinctions which are not evident from the body fossil record. Unique examples of the non-hominin mammalian ichnosites include sand-swimming traces that resemble those of the ‘Namib mole’: as a result a new ichnogenus (Natatorichnus) has been erected, containing two ichnospecies, N. subarenosa and N. sulcatus. The first elephant trunk-drag impressions and the first pinniped ichnosites in the global record have been identified. The role of elephant tracks as precursors to coastal potholes was previously unsuspected. Equid tracksites indicate a widespread presence of the extinct giant Cape horse (Equus capensis). The identification of a giraffe tracksite represents a major range extension. In particular, tracks and traces of giraffe, crocodiles, breeding sea turtles, and sand-swimming golden moles have significant palaeoenvironmental implications.
- Description
- Thesis (PhD) -- Faculty of Science, School of Environmental Sciences, 2023
- Format
- computer
- Format
- online resource
- Format
- application/pdf
- Format
- 1 online resource (426 pages), Illustrations
- Format
- Publisher
- Nelson Mandela University
- Publisher
- Faculty of Science
- Language
- English
- Rights
- Nelson Mandela University
- Rights
- All Rights Reserved
- Rights
- Open Access
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| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | SOURCE1 | Helm, CW.pdf | 9 MB | Adobe Acrobat PDF | View Details Download |