Volume 15 1973
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Item HIGH INHERITANCE ELONGATE STROMATOLITIC MOUNDS FROM THE TRANSVAAL DOLOMITE(BERNARD PRICE INSTITUTE FOR PALAEONTOLOGICAL RESEARCH, 1973) Eriksson, K. A.; Truswell, J. F.Elongate mound·like structures up to 10 metres across and 40 metres in length are described. Characteristic features of the mounds are their high inheritance and considerable relief which, along with the absence of sub-aerial exposure features, the fine-grained nature of the carbonate, and their vertical persistence, are taken to suggest a subtidal origin. Marine currents are considered adequate to account for their elongation.Item THE MODE OF LIFE OF GORGONOPSIANS(BERNARD PRICE INSTITUTE FOR PALAEONTOLOGICAL RESEARCH, 1973) Cruickshank, A. R. I.The gorgonopsians as typically developed were undoubtedly the dominant land carnivores of the Upper Permian and have been compared with the sabre-tooth cats of the Tertiary (Parrington, 1955, p. 7 and Kemp, 1969b, p. 321). However, the similarities between the two groups are almost entirely confined to their dentitions and the general proportions of their lower jaws, both possessing greatly enlarged canine teeth and relatively weak coronoid processes on the lower jaw. In addition, both groups show adaptations to allow the lower jaw to make a wide gape, thus allowing the upper and lower canines to clear each other when the jaw is opened and, at the same time, keeping the jaw articulations from dislocating during this movement.Item A NEW DICTYOPYGID FROM THE CAVE SANDSTONE OF LESOTHO, SOUTHERN AFRICA(BERNARD PRICE INSTITUTE FOR PALAEONTOLOGICAL RESEARCH, 1973) Forey, P.; Gardiner, B. G.The Lower Triassic of South Africa has yielded an array of early dictyopygids (Brough, 1931, 1936) yet none of those advanced dictyopygids so characteristic of the Upper Triassic of North America (Schaeffer, 1967) has so far been recorded from the African continent. The geographical distribution of the dictyopygids appears to be a discontinuous one with the Lower Triassic forms coming mainly from South Africa, the Middle Triassic ones from Australia and the Upper Triassic forms from North America. It is thus surprising to find a seemingly advanced dictyopygid in the rather unfossiliferous Cave Sandstone of Lesotho.Item NEW PALAEOZOIC FISH REMAINS FROM SOUTHERN AFRICA(BERNARD PRICE INSTITUTE FOR PALAEONTOLOGICAL RESEARCH, 1973) Gardiner, B. G.The fossil fish record of southern Africa is both sparse and spotty and the only group with a relatively complete record is the Actinopterygii; indeed several of the major fish groups have not so far been described from the African Continent. The Palaeozoic rocks of southern Africa have yielded an even more restricted fish fauna (Gardiner 1962; 1969). However, an accumulation of new, but fragmentary, material from several localities has shown the undoubted presence of two groups, coelacanths and acanthodians, hitherto unrecorded from the Palaeozoic strata of southern Africa.Item Palaeontologia africana Volume 15 Part 1(Bernard Price Institute for Palaeontological Research, 1973)Item Palaeontologia africana Volume 15 Part 2(Bernard Price Institute for Palaeontological Research, 1973)Item PROBLEMATIC MICROFOSSILS FROM THE LOWER KARROO BEDS IN SOUTH AFRICA(BERNARD PRICE INSTITUTE FOR PALAEONTOLOGICAL RESEARCH, 1973) McLachlan, I. R.A problematic group of microfossils has recently been recovered from strata of Permian age, in the northern part of the Karroo basin in South Africa. This article attempts to present the information that is presently known about them. They have been found in a wide variety of sediments in the Lower, Middle and Upper Ecca stages, and in carbonaceous sediments in the lower part of the Beaufort series. The external morphology of the microfossils is extremely varied, but they are characterized by a regular cup-shaped organ. They closely resemble forms called Anellotubulata by O. Wetzel (1959), who described them from the Upper Lias (c) of Germany. Other workers have recovered, but not described, similar microfossils from Permian, Triassic and Cretaceous strata in Australia. In this paper, the microfossils are referred to as anellotubulates. They are remarkable in a number of respects, the most extraordinary of which is their composition. Electron-microprobe and X-ray diffraction tests have shown the shell to consist of a non-crystalline mineral or minerals, composed mainly of iron and phosphorus, with minor calcium. It has not been possible to demonstrate clearly whether this is the original shell composition, or whether it has resulted from replacement. The available information, including that provided by associated fossils, which has bearing on the palaeoenvironment of the anellotubulates, is discussed. It is hoped that, when more information is available, these problematic microfossils will contribute towards a better understanding of the depositional environment of the sediments in which they occur.Item A REVIEW OF THE EVIDENCE FOR MARINE CONDITIONS IN SOUTHERN AFRICA DURING DWYKA TIMES(BERNARD PRICE INSTITUTE FOR PALAEONTOLOGICAL RESEARCH, 1973) McLachlan, I. R.; Anderson, AnnThe faunas of the three major Dwyka basins in southern Africa are listed in the form of tables. Marine invertebrates have been recorded from the western part of the Kalahari basin and from the Warmbad basin, but had not previously been confirmed within the Great Karroo basin. A new fauna from the base of the Upper Dwyka shales near Kimberley is described. Cephalopods, brachiopods and lamellibranchs are found in calcareous concretions, which also contain palaeoniscoid fish, coprolites, fossil wood and the mineral glauberite. The marine invasion into South West Africa postulated by Martin & Wilczewski (1970) therefore extended into the Great Karroo basin as well. By the time of accumulation of the White Band at the top of the Upper Dwyka shales, conditions were probably non-marine; with the possible exception of the Notocarid crustaceans, the White Band fossils are not, in themselves, indicative of marine conditions. The only other significant indication of marine conditions in the Great Karroo basin is the glauconite in the deltaic Coal Measures of the Ecca in the northern part of the basin. It is possible then that the fossiliferous marine shales near Kimberley accumulated as a fine-grained offshore facies of the Ecca deltaic sequence.