Permo-Triassic fossil woods from the South African Karoo Basin

The Karoo Basin extends over more than half of the South African land surface and incorporates sediments deposited over a period of more than 100 million years, from the Upper Carboniferous to the Lower Jurassic. Biozones have been established on the basis of the abundant vertebrate fauna. Fossil plant deposits are numerous but best represented by the Lower Permian Glossopteris floras and Middle to Upper Triassic Dicroidium floras. Fossil woods occur throughout the sequence. In this paper previously described woods are discussed, newly collected woods are described and an attempt is made to correlate the woods with the Formations and vertebrate biozones. Prototaxoxylon africanum (Walton) Krausel and Dolianiti is common but restricted to the Permian (Ecca and Lower Beaufort Groups). Prototaxoxylon uniseriale Prasad has the same distribution but is rare. Australoxylon teixeirae Marguerier extends from the Ecca to the middle Beaufort. Araucarioxylon occurs throughout the Karoo but there are several species that have different ranges. Araucarioxylon africanum Bamford sp. nov. occurs throughout the Beaufort and into younger deposits. Araucarioxylon karooensis Bamford sp. nov. occurs in the Normandien Formation of the Beaufort Group. Woods with podocarpacean affinities, recognized as Mesembrioxylon, first occur in the uppermost Beaufort and extend into the Cretaceous. The woods can, therefore, be used as broadscale biostratigraphic indicators but further data need to be collected.The Council's Research Committe, University of the Witwatersrand; National Science Foundatio

Carboniferous pycnoxylic woods from the Dwyka Group of southern Namibia

Glacial deposits of the Dwyka Group between Keetmanshoop and Mariental in southern Namibia have been reinvestigated for palaeontological remains and associated tuff horizons in an attempt to accurately date the deposits. SHRIMP-based dating of juvenile zircons from these tuff horizons provide ages which cumulate in the latest Carboniferous (Gzelian). The pycnoxylic woods Megaporoxylon scherziKrausel and Megaporoxylon kaokense Krausel are described in detail for the first time and are compared with similar permineralised woods from Gondwana. Based on previous fossil wood studies covering the rocks of the main Karoo Basin, these species occur only in the Dwyka and lower Ecca Groups in southern Africa and do not extend to the upper Ecca Group.The Council's Research Committee, University of the Witwatersrand; National Research Foundation (NRF); Palaeo-Anthropology Scientific Trust (PAST); German Research Foundation (DFG) and the Postgraduate Research Program "Interdisciplinary Geoscience Research in Africa

A submerged Late Cretaceous podocarpaceous forest, west coast, South Africa

During mini-submersible dives in De Beers offshore concessions on the middle shelf of Namaqualand, on the west coast of South Africa, a fossil forest was located and sampled. Over an area of 2 km2 there are numerous in situ and prostrate trunks on a gentle slope, 136-140 m below sea level and about 32 km offshore. Micro-palaeontological dating shows that the sediments are of Coniacian age. The silicified woods have been identified as members of the Podocarpaceae and one new species is described, Podocarpoxylon jago Bamford & Stevenson sp. nov. The second species identified is P. umzambense Schultze-Motel. These woods are compared with other west coast woods, both onshore and offshore, and the Upper Cretaceous coastal environment is postulated

Fossil wood of Cretaceous age from the Namaqualand continental shelf, South Africa

Fossil wood was collected from sediments on the Namaqualand shelf, West Coast, South Africa, between the Orange River mouth and just to the south of Kleinzee. Forty three of these samples are here described. All the woods are gymnospermous and have abietinian tracheid pitting. Nineteen of them are well enough preserved to be identified to species level: Podocarpoxylon cf. umzambense, Mesembrioxylon cf. stokesii, M. cf. sahnii, M. cf. woburnense and Protocupressinoxylon cf. purbeckensis. The remainder of the woods have been placed in the artificial genus Mesembrioxylon without species names. The woods are probably primitive members of the Podocarpaceae growing during the Lower Cretaceous. They indicate a seasonal climate and inhabited the extensive low-lying coastal regions.De Beer

More fossil wood from the Namaqualand coast, South Africa; onshore material.

Main articleFossil wood was collected from a palaeo-beach sequence on the farms Sandkop, Oubeep and adjacent State land, on the Namaqualand (west) coast of South Africa. Of the 14 samples sectioned only 5 were well enough preserved to describe and identify to species level. The woods are podocarpaceous and have been assigned to the taxa Podocarpoxylon cf. umzambense, Mesembrioxylon woburnense, M. stokesi and Mesembrioxylon sp. The samples are Lower Cretaceous in age and were most probably reworked a number of times into successively younger palaeoshoreline deposits. The same species occurred in the offshore sediments, therefore indicating a wider area of "woodland" and further evidence of extensive shelf erosion by subsequent marine transgressions and regressions.Non

Taxonomic description of fossil wood from Cainozoic Sak River terraces, near Brandvlei, Bushmanland, South Africa

Seven pieces of silicified wood are described from two sites near the Sak River, Bushmanland. The Miocene deposit yielded five specimens which can be assigned to the Dipterocarpaceae, Fagaceae, Myrtaceae, Oleaceae and Rutaceae. Of the two logs recovered from the Plio-Pleistocene deposit, only one was well enough preserved to be assigned to the Polygalaceae. All the woods indicate that the palaeoenvironment in that region was tropical to subtropical based on the wood structure, growth rings and from their modem counterparts.De Beer

Fossil tree hollows from a late Permian forest of the Matinde Formation (Tete, Mozambique)

Fossil tree hollows are seldom described in the literature and can often be elusive to the field paleobotanist. However, these structures may provide unique paleoecological, environmental and tree life history information that are essential for a more complete understanding of ancient forests. A stump from the ‘late Permian’ (Wuchiapingian–Changhsingian) of the Mágoè Fossil Forest in Mozambique (Tete Province) provides a rare example of fossilized tree hollows. These hollows were found near the base of the tree and are subcircular in shape, ranging between ~1.3 and 3.5 cm in diameter. Although thirty-one trees were densely sampled (i.e. no fossil trees were excluded from a given area, in our case ~2650m2) and inspected at the Mágoè Fossil Forest, only one (PPM2017-31) exhibited tree hollows, highlighting the scarcity of these structures in this fossil forest. In modern forests tree hollows are more likely to be found in old trees, likewise PPM2017-31 was among the largest trees found in the sample, suggesting this was an old tree. The subcircular morphology of the tree hollows indicates they resulted from fungal/bacterial activity rather than from a fire.Museu Nacional de Geologia Fundação para a Ciência e a Tecnologia (SFRH/BPD/96205/2013) FCT - AGA KHAN Development Network grant number 333206718 National Geographic Society grant number CP-109R-17JNC201

Isotopic evidence for contrast diets of early hominins Homo habilis and Australopithecus boisei of Tanzania

Isotopic dietary studies of early hominins have hitherto been confined to specimens from South Africa. We are now able to report isotopic analyses of two species of early hominins from Tanzania : Homo habilis and Australopithecus boisei. The results show that these two species had very different diets. The isotopic analyses of three South African species of early hominins, in contrast, show considerable variation in individual diets, but no marked differences between species

A fossil peat deposit from the Late Triassic (Carnian) of Zimbabwe with preserved cuticle of Pteridospermopsida and Ginkgoales, and its geological setting

Well-preserved cuticular material of Pteridospermopsida and Ginkgoales from the Late Triassic of Zimbabwe is described here for the first time. It is preserved within a brown peat-like lens in the Upper Karoo Angwa Sandstone Formation. The locality is on the Manyima River in the lower portion of the mid-Zambezi Valley of Zimbabwe. Using SEM and light microscopy to identify the taxa, the fragmentary cuticles are of Pteridospermopsida type and have been assigned to Lepidopteris sp. (Peltaspermales) and Dicroidium sp. A, B, (Corystospermales). Cuticles of the ginkgoalean leaf genus, Sphenobaiera, are also described. Well-preserved ovules were found in close association with the cuticles, but as the stomata are not visible they cannot be assigned to any genus. Based on their close similarity to the Dicroidium flora of the South African Upper Karoo, the plants are considered to be equivalent to the South African Molteno Formation in age (Carnian). The palynoflora supports this age bracket, as does fauna preserved nearby. The taphonomic process was one of transport, sorting and deposition in a fluvial system.The CNRS-NRF agreement between France and South Afric

A Late Devonian refugium for Colpodexylon (Lycopsida) at high latitude

peer reviewedLocalities within strata of the Witpoort Formation (Witteberg Group, Cape Supergroup) of South Africa provide diverse new fossil material of Famennian plants from a high palaeolatitude marginal marine setting. Lycopsid axes with sterile leaves include material here diagnosed to two new species of Colpodexylon Banks 1944. C. pullumpedes sp. nov. from Waterloo Farm is a ‘short-tipped’ species, whereas C. mergae sp. nov. from Coombs Hill, is a ‘long-tipped’ species. The latter has leaves similar to those of the type species, C. deatsii Banks, yet differing in proportions. This provides the first definite high latitude records of the genus. Furthermore, these occurrences substantially extend the temporal range of Colpodexylon, formerly only known from lower Frasnian and older strata, indicating that the genus persisted at high-latitudes after its apparent disappearance from the palaeo-sub-tropics