High-latitude Chondrichthyans from the Late Devonian (Famennian) Witpoort formation of South Africa

Coral communities display spatial patterns. These patterns can manifest along a coastline as well as across the continental shelf due to ecological interactions and environmental gradients. Several abiotic surrogates for environmental variables are hypothesised to structure high-latitude coral communities in South Africa along and across its narrow shelf and were investigated using a correlative approach that considered spatial autocorrelation. Surveys of sessile communities were conducted on 17 reefs and related to depth, distance to high tide, distance to the continental shelf edge and to submarine canyons. All four environmental variables were found to correlate significantly with community composition, even after the effects of space were removed. The environmental variables accounted for 13% of the variation in communities; 77% of this variation was spatially structured. Spatially structured environmental variation unrelated to the environmental variables accounted for 39% of the community variation. The Northern Reef Complex appears to be less affected by oceanic factors and may undergo less temperature variability than the Central and Southern Complexes; the first is mentioned because it had the lowest canyon effect and was furthest from the continental shelf, whilst the latter complexes had the highest canyon effects and were closest to the shelf edge. These characteristics may be responsible for the spatial differences in the coral communities.

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A tetrapod fauna from within the Devonian Antarctic Circle

Science ◽

10.1126/science.aaq1645 ◽

2018 ◽

Vol 360 (6393) ◽

pp. 1120-1124 ◽

Cited By ~ 9

Author(s):

Robert Gess ◽

Per Erik Ahlberg

Keyword(s):

South Africa ◽

North America ◽

Late Devonian ◽

Body Fossil ◽

The Antarctic

Until now, all known fossils of tetrapods (limbed vertebrates with digits) and near-tetrapods (such asElpistostege,Tiktaalik, andPanderichthys) from the Devonian period have come from localities in tropical to subtropical paleolatitudes. Most are from Laurussia, a continent incorporating Europe, Greenland, and North America, with only one body fossil and one footprint locality from Australia representing the southern supercontinent Gondwana. Here we describe two previously unknown tetrapods from the Late Devonian (late Famennian) Gondwana locality of Waterloo Farm in South Africa, then located within the Antarctic Circle, which demonstrate that Devonian tetrapods were not restricted to warm environments and suggest that they may have been global in distribution.

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Long-term community changes on a high-latitude coral reef in the Greater St Lucia Wetland Park, South Africa

Marine Pollution Bulletin ◽

10.1016/j.marpolbul.2007.11.011 ◽

2008 ◽

Vol 56 (3) ◽

pp. 493-502 ◽

Cited By ~ 37

Author(s):

Michael H. Schleyer ◽

Alke Kruger ◽

Louis Celliers

Keyword(s):

South Africa ◽

Coral Reef ◽

High Latitude ◽

Community Changes

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New arthrodires (placoderm fishes) from the Aztec Siltstone (late Middle Devonian) of southern Victoria Land, Antarctica

Australian Journal of Zoology ◽

10.1071/zo13070 ◽

2014 ◽

Vol 62 (1) ◽

pp. 44 ◽

Cited By ~ 4

Author(s):

Gavin C. Young ◽

John A. Long

Keyword(s):

South Africa ◽

New Taxa ◽

Middle Devonian ◽

Late Devonian ◽

Dorsal Plate ◽

Victoria Land ◽

Small Collection ◽

Vertebrate Assemblage ◽

Devonian Age

A small collection of arthrodire remains is described from the Devonian Aztec Siltstone of southern Victoria Land, Antarctica. Barwickosteus antarcticus, gen. et sp. nov., is a small phlyctaeniid arthrodire probably closely related to Barrydalaspis from the Bokkeveld Group of South Africa. Grifftaylor antarcticus, gen. et sp. nov., is a generalised phlyctaeniid resembling Phlyctaenius and Neophlyctaenius. New specimens of Boomeraspis show that it had a high-spired trunk-armour with a median dorsal plate of similar proportions to Tiaraspis, Mithakaspis, Turrisaspis or Africanaspis. Other fragmentary median dorsal plates are provisionally referred to Turrisaspis and Mulgaspis. With these new taxa the vertebrate assemblage from the Aztec Siltstone comprises at least 37 genera and 50 species, making it one of the most diverse of Middle–Late Devonian age.

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Climate change and coral reefs: different effects in two high-latitude areas (Arabian Gulf, South Africa)

Coral Reefs ◽

10.1007/s00338-003-0335-0 ◽

2003 ◽

Vol 22 (4) ◽

pp. 433-446 ◽

Cited By ~ 120

Author(s):

B. Riegl

Keyword(s):

Climate Change ◽

South Africa ◽

Coral Reefs ◽

High Latitude ◽

Arabian Gulf

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Coombs Hill: A Late Devonian fossil locality in the Witpoort Formation (Witteberg Group, South Africa)

South African Journal of Science ◽

10.17159/sajs.2021/9190 ◽

2021 ◽

Vol 117 (3/4) ◽

Author(s):

Christopher Harris ◽

Robert W. Gess ◽

Cameron Penn-Clarke ◽

Bruce S. Rubidge

Keyword(s):

South Africa ◽

Sedimentary Facies ◽

High Energy ◽

Bivalve Mollusc ◽

Structural Deformation ◽

Late Devonian ◽

Fossil Plants ◽

Taxonomic Analysis ◽

Coastal Marine ◽

Devonian Extinction

Coombs Hill, a new fossil locality in the Witpoort Formation (Witteberg Group) of South Africa, preserves a record of Famennian (Late Devonian) life in Gondwana. Fossil plants collected at Coombs Hill are preliminarily assigned to several classes. Shelly invertebrates include a variety of bivalve mollusc forms, some of which appear to be preserved in life position. Biodiversity at Coombs Hill is comparable to that of the well-known Waterloo Farm lagerstätte in ordinal diversity, but exhibits differences in species composition. Ongoing taxonomic analysis will provide a rare window into the ecology of high-latitude environments during this pivotal stage of Earth history, which immediately preceded the end-Devonian extinction. Sandstone dominated sedimentary facies at Coombs Hill suggest a high-energy coastal marine setting, with brackish back-barrier estuarine/lagoonally derived fossiliferous mudstones. Exact stratigraphic placement within the Witpoort Formation is hampered by structural deformation, and precise age comparisons with Waterloo Farm are currently tenuous.

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