Pleistocene large reptile tracks and probable swim traces on South Africa’s Cape south coast

Charles W. Helm; Hayley C. Cawthra; Xander Combrink; Carina J.Z. Helm; Renée Rust; Willo Stear; Alex van den Heever

doi:10.17159/sajs.2020/6542

Authors

Charles W. Helm 1. African Centre for Coastal Palaeoscience, Nelson Mandela University, Port Elizabeth, South Africa; 2. Peace Region Palaeontology Research Centre, Tumbler Ridge, British Columbia, Canada https://orcid.org/0000-0001-7995-8809
Hayley C. Cawthra 1. African Centre for Coastal Palaeoscience, Nelson Mandela University, Port Elizabeth, South Africa; 2. Geophysics and Remote Sensing Unit, Council for Geoscience, Cape Town, South Africa https://orcid.org/0000-0002-6101-5543
Xander Combrink Department of Nature Conservation, Tshwane University of Technology, Pretoria, South Africa https://orcid.org/0000-0003-0404-7773
Carina J.Z. Helm Department of Geography, University of British Columbia, Vancouver, British Columbia, Canada https://orcid.org/0000-0002-0183-2015
Renée Rust School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand, Johannesburg, South Africa https://orcid.org/0000-0003-0252-5436
Willo Stear African Centre for Coastal Palaeoscience, Nelson Mandela University, Port Elizabeth, South Africa https://orcid.org/0000-0002-9996-9828
Alex van den Heever Tracker Academy, Magazine Hill, Graaff-Reinet, South Africa https://orcid.org/0000-0002-5289-9527

DOI:

https://doi.org/10.17159/sajs.2020/6542

Keywords:

Pleistocene reptiles, fossil tracks, swim traces, crocodylians, lithics

Abstract

The Cape south coast of South Africa contains a wealth of Pleistocene vertebrate trace fossil sites in aeolianites and cemented foreshore deposits. Published studies have described mammal and avian tracksites identified along this coastline. We report here on a number of Pleistocene palaeosurfaces within the Garden Route National Park that exhibit tracks of large reptiles, including probable swim traces. The tracks were probably made by more than one species, and may include a crocodylian. There are no extant reptiles in this coastal region capable of making such tracks and traces, which probably represent an indication of a previously more extensive range for the Nile crocodile and a monitor lizard. These findings demonstrate the potential for ichnology to complement the traditional body fossil record. Two Middle Stone Age stone artifacts were found embedded in one palaeosurface containing multiple reptile trackways. These discoveries have implications for the understanding of Pleistocene palaeoenvironment and palaeoclimate – in an area which is important in the study of modern human origins.

Significance:

Large reptile Pleistocene fossil tracksites have recently been discovered on the Cape south coast of South Africa where there are no previous such records, and no reptiles of this size are currently found in the region.
These sites include the first reported probable reptile swim traces in Africa and one tracksite also contained two Middle Stone Age artifacts.
These discoveries have implications for Pleistocene environments and climate on the Cape south coast.