Stepping out across the Karoo retro-foreland basin: Improved constraints on the Ecca-Beaufort shoreline along the northern margin

Groenewald, David P.; Day, Michael O.; Penn-Clarke, Cameron R.; Rubidge, Bruce S.

doi:10.1016/j.jafrearsci.2021.104389

Cited by 6 publications

(11 citation statements)

References 107 publications

(223 reference statements)

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“…2020; Groenewald et al . 2022). This regional‐scale diachroneity is also supported by the AZ communities as a younging of the AZs away from the foredeep region, as older sedimentary units laterally attenuate over hundreds of kilometres (Kitching 1977; Catuneanu et al .…”

Section: Discussionmentioning

confidence: 99%

Network‐based biostratigraphy for the late Permian to mid‐Triassic Beaufort Group (Karoo Supergroup) in South Africa enhances biozone applicability and stratigraphic correlation

et al. 2022

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The Permo‐Triassic vertebrate assemblage zones (AZs) of South Africa's Karoo Basin are a standard for local and global correlations. However, temporal, geographical and methodological limitations challenge the AZs reliability. We analyse a unique fossil dataset comprising 1408 occurrences of 115 species grouped into 19 stratigraphic bin intervals from the Cistecephalus, Daptocephalus, Lystrosaurus declivis and Cynognathus AZs. Using network science tools we compare six frameworks: Broom, Rubidge, Viglietti, Member, Formation, and one suggesting diachroneity of the Daptocephalus/Lystrosaurus AZ boundary (Gastaldo). Our results demonstrate that historical frameworks (Broom, Rubidge) still identify the Karoo AZs. No scheme supports the Cistecephalus AZ, and it probably comprises two discrete communities. The Lystrosaurus declivis AZ is traced across all frameworks, despite many shared species with the underlying Daptocephalus AZ, suggesting that the extinction event across this interval is not a statistical artefact. A community shift at the upper Katberg to lower Burgersdorp formations may indicate a depositional hiatus which has important implications for regional correlations, and Mesozoic ecosystem evolution. The Gastaldo model still identifies a Lystrosaurus and Daptocephalus AZ community shift, does not significantly improve recent AZ models (Viglietti), and highlights important issues with some AZ studies. Localized bed‐scale lithostratigraphy (sandstone datums), and singleton fossils cannot be used to reject the patterns shown by hundreds of fossils, and regional chronostratigraphic markers of the Karoo foreland basin. Metre‐level occurrence data suggests that 20–50 m sampling intervals capture Karoo AZs, unifying the use of metre‐level placements of singleton fossils to delineate biozone boundaries and make regional correlations.

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Section: Discussionmentioning

confidence: 99%

Network‐based biostratigraphy for the late Permian to mid‐Triassic Beaufort Group (Karoo Supergroup) in South Africa enhances biozone applicability and stratigraphic correlation

et al. 2022

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“…A recent detailed appraisal of the sedimentology and lithostratigraphy across the Ecca-Beaufort contact in the north of the main Karoo Basin may be found in Groenewald et al . [ 37 ] and is referred to herein. The described study complied with all relevant regulations and the necessary permit (REF: SAH19/13092) was obtained from KwaZulu-Natal Amafa and Research Institute.…”

Section: Methodsmentioning

confidence: 99%

“…Named in honour of the late Mr Dave Green, who discovered this remarkable site and had a passion for palaeontology, the Dave Green palaeosurface (S28.967122˚, E29.987366˚) is located along a tributary of the Rensburgspruit on the farm Van der Merwe's Kraal 972, approximately 10 km northeast of the town Estcourt in KwaZulu-Natal Province, South Africa (Figs 1 and 2). The region spans the Ecca-Beaufort transition and is primarily underlain by late Permian (Changhsingian) siliciclastic deposits of the Waterford and Balfour formations that are intruded by lower Jurassic dolerite dykes and sills [32][33][34][35][36][37]. The Dave Green palaeosurface covers an area of approximately 600 m 2 and is situated in the upper Waterford Formation, immediately below the Ecca-Beaufort contact, which records the transition from marine/ lacustrine to fluvial environmental conditions [31,[34][35][36][37].…”

Section: Geological and Palaeontological Contextmentioning

confidence: 99%

“…The region spans the Ecca-Beaufort transition and is primarily underlain by late Permian (Changhsingian) siliciclastic deposits of the Waterford and Balfour formations that are intruded by lower Jurassic dolerite dykes and sills [32][33][34][35][36][37]. The Dave Green palaeosurface covers an area of approximately 600 m 2 and is situated in the upper Waterford Formation, immediately below the Ecca-Beaufort contact, which records the transition from marine/ lacustrine to fluvial environmental conditions [31,[34][35][36][37].…”

Section: Geological and Palaeontological Contextmentioning

confidence: 99%

“…Laccosaurus ) and fragmentary dicynodont material. Although the body fossils are not diagnostic, the lowermost vertebrate assemblage zone of the Beaufort Group in this part of KwaZulu-Natal is the late Permian (Lopingian) Daptocephalus Assemblage Zone (AZ), although it is unclear which subzone is present [ 37 , 57 ].…”

Section: Introductionmentioning

confidence: 99%

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Unique trackway on Permian Karoo shoreline provides evidence of temnospondyl locomotory behaviour

et al. 2023

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Large-bodied temnospondyl amphibians were the dominant predators in non-marine aquatic ecosystems from the Carboniferous to the Middle Triassic. In the Permian-aged lower Beaufort Group of the main Karoo Basin, South Africa, temnospondyls are represented exclusively by the family Rhinesuchidae and are well represented by body fossils, whereas trace fossils are scarce. Accordingly, most interpretations of the behaviour of this family are based on skeletal morphology and histological data. Here we document the sedimentology and palaeontology of a late Permian palaeosurface situated immediately below the palaeoshoreline of the Ecca Sea (transition from the Ecca Group to the Beaufort Group) near the town of Estcourt in KwaZulu-Natal Province. The surface preserves numerous ichnofossils, including tetrapod footprints and fish swim-trails, but most striking are seven body impressions and associated swim trails that we attribute to a medium-sized (~1.9 m long) rhinesuchid temnospondyl. These provide valuable insight into the behaviour of these animals. The sinuous shape of some of the traces suggest that the tracemaker swam with continuous sub-undulatory propulsion of the tail.

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Trophic niche patterns of endangered Sandelia bainsii and Amatolacypris trevelyani in the Eastern Cape, South Africa: Insights from stable isotope analysis

Kadye,

Nkomo,

Kambikambi

et al. 2024

Aquatic Conservation

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Despite supporting a disproportionately large fraction of the global biodiversity, freshwater ecosystems are ranked as the most highly threatened habitats ahead of both terrestrial and marine ecosystems. Furthermore, many regions are still characterized by limited knowledge on taxonomy and ecology of freshwater fishes. The need for ecological information in understudied regions is important particularly where there are recent discoveries of new species and unique lineages and for threatened and endangered taxa that require conservation management. This study evaluated the trophic ecology of two freshwater fish species Sandelia bainsii and Amatolacypris trevelyani that are both classified as endangered in the International Union for Conservation of Nature (IUCN) Red List. These two species, which are narrow‐range endemics in the Eastern Cape, South Africa, comprise allopatric lineages whose ecology is poorly known. This study used stable isotope analysis to evaluate the food web patterns, explore the trophic niche dynamics and estimate the prey source contributions for the two species in different headwater habitats. The fishes isotopic niche sizes were spatially variable, suggesting the likely importance of stochastic variation in resource availability and probable interspecific interactions. The three lineages within S. bainsii exhibited low isotopic niche overlap onto those of sympatric fishes in most habitats. Isotopic mixing model revealed that these lineages' diets were mostly dominated by gatherers/collectors. In comparison, the two lineages within A. trevelyani exhibited high niche overlap with other species and generally had variable diets. Despite the low and high niche overlap patterns of S. bainsii and A. trevelyani, respectively, the isotopic niche overlap patterns of co‐occurring species onto those of the former suggest the likely lack of competitive hierarchies. The trophic niche patterns of these two endangered species helped to shed some light on the potential invasion risks by non‐piscivorous fishes with opportunistic feeding habits, which could exert competitive interspecific interactions.

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Stepping out across the Karoo retro-foreland basin: Improved constraints on the Ecca-Beaufort shoreline along the northern margin

Cited by 6 publications

References 107 publications

Network‐based biostratigraphy for the late Permian to mid‐Triassic Beaufort Group (Karoo Supergroup) in South Africa enhances biozone applicability and stratigraphic correlation

Network‐based biostratigraphy for the late Permian to mid‐Triassic Beaufort Group (Karoo Supergroup) in South Africa enhances biozone applicability and stratigraphic correlation

Unique trackway on Permian Karoo shoreline provides evidence of temnospondyl locomotory behaviour

Trophic niche patterns of endangered Sandelia bainsii and Amatolacypris trevelyani in the Eastern Cape, South Africa: Insights from stable isotope analysis

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