Volume 38 2002
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Browsing Volume 38 2002 by Type "Article"
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Item A brachyopid temnospondyl from the lower Cynognathus Assemblage Zone In the northern Karoo Basin, South Africa(Bernard Price Institute for Palaeontological Research, 2002) Damiani, Ross J.; Jeannot, Ashleigh M.A new brachyopid temnospondyl is described from the Early to Middle Triassic Cynognathus Assemblage Zone of the upper Beaufort Group, Karoo Basin of South Africa. It is the fourth named brachyopid from the Karoo and the first from the northern part of the basin. Despite the incomplete nature of the holotype skull, the new brachyopid apparently shows closest affinities to Batrachosuchus watsoni. However, differences in the width of the sensory sulci, the absence of a transverse occipital sulcus, and the presence of a unique narial morphology, warrants separation at the species level. The holotype skull also provides insight into the morphology of the ventral surface of the skull roof and the configuration of the bones between the orbit and the nostril. A referred right mandibular ramus, the most complete yet recovered of a brachyopid, also shows several unique features. A reconsideration of the taxonomy of the brachyopid genus Batrachosuchus reveals that Batrachosuchus watsoni possesses several characters distinct from the type species, Batrachosuchus browni, and is thus transferred to a new genus. In addition, 'Batrachosuchus' henwoodi and Batrachosuchus concordi probably do not pertain to the genus Batrachosuchus. Brachyopid diversity in the Karoo is exceeded only by the Mastodonsauridae and Rhinesuchidae, and they may eventually prove to be important aids in the biostratigraphy of the Cynognathus Assemblage Zone.Item Character state transformations and the fit of phylogenies to the fossil record(Bernard Price Institute for Palaeontological Research, 2002) Angielczyk, Kenneth DThere is only one true history of life, and the biostratigraphic record and the phylogenetic relationships of organisms provide the most important information regarding this history. Ideally, the historical signal preserved in each of the data sets should be the same, and several methods have been proposed to compare the fit of phylogenies to the fossil record. All of these techniques use stratigraphic data associated with taxa, but our ability to recognize taxa and reconstruct their phylogenetic relationships ultimately is based on patterns of character state distributions that we observe. This raises the question of whether character states can be used to measure the fit of a phylogeny to the fossil record. Here I argue that we can, if the order of appearance of character states is considered. Optimization of character states on a phylogeny results in a predicted order of appearance of character states; derived states must arise after basal states. This order can be compared to that predicted by the fossil record. Although a number of factors can affect the frequency at which derived character states are sampled before basal states in the fossil record, conflicts between the two data sets should be relatively rare. Phylogenies that imply a large number of character state transformations that are inconsistent with the fossil record may need to be reconsidered before the fossil record is criticized.Item A dicynodont trackway from the Cistecephalus Assemblage Zone in the Karoo, East of Graaff-Reinet, South Africa(Bernard Price Institute for Palaeontological Research, 2002) de Klerk, William JThis paper reports a partially exposed late Permian palaeosurface with preserved vertebrate tracks at the "Asante Sana" private game reserve in the vicinity of Petersburg, 46km east of Graaff-Reinet. Excavation of the palaeosurface over an area of 34m2 revealed clear footprints and trackways of six large tetrapods that walked in a westerly direction across a semi-consolidated muddy substrate in the distal floodplain area of a large fluvial system. Clear heteropodous impressions of the footpads and individual toes and claws are preserved as concave epirelief moulds. It is concluded that these fossil tracks were made by a group of therapsids, specifically a group of large dicynodonts, possibly Aulacephalodon. The tracks are here assigned to the ichnospecies Dicynodontipus icelsi sp. nov. A continuous trackway and numerous less distinct individual prints and markings made by smaller tetrapods are also preserved on the palaeosurface. It is probable that these tracks were left by Diictodon, a small common dicynodont of the time.Item First record of non-mammalian cynodonts (Therapsida) in the Sanga do Cabral Formation (Early Triassic) of southern Brazil(2002) Abdala, Fernando; Dias-de-Silva, Sergio; Cisneros, Juan CNew material from the Sanga do Cabral Formation in southern Brazil is described, including one distal and three proximal portions of femora, and a distal portion of a humerus. Comparative studies indicate affinities of the proximal femora and the distal humerus with non-mammalian cynodonts, whereas the distal femur cannot be attributed with certainty to this group. These postcranial elements are the first record of non-mammalian cynodonts for the Sang a do Cabral Formation and demonstrate the presence of small- to medium-sized representatives of this group in the Early Triassic fauna of Brazil.Item A new genus of ovuliferous glossopterid fructifications from South Africa(Bernard Price Institute for Palaeontological Research, 2002) Adendorff, R.; McLoughlin, S.; Bamford, M. K.A new genus of Early Permian glossopterid fructifications, Gladiopomum, is established to accommodate pedicellate, capitate fructifications with narrow receptacles, apical spines, and very broad wings. Two species recognized within this genus were previously assigned to Scutum Plumstead and Hirsutum Plumstead, viz., G. dutoitides (Plumstead) comb. nov. and G. acadarense (Anderson & Anderson) comb. nov. An additional species, G. elongatum sp. nov. is established based on material from a new fossil locality at Rietspruit Colliery in the northern Karoo Basin. All species of Gladiopomum are confined to the Vryheid Formation; the genus may constitute a useful biostratigraphic index taxon for Artinskian strata throughout the Karoo Basin.Item A new late Permian ray-finned (actinopterygian) fish from the Beaufort Group, South Africa(Bernard Price Institute for Palaeontological Research, 2002) Bender, PatrickA new genus and species of actinopterygian (ray-finned) fish, Kompasia delaharpei, is described from Late Permian (Tatarian) fluvio-lacustrine, siltstone dominated deposits within the lower Beaufort Group of South Africa. It is currently known from two localities on adjoining farms, Wilgerbosch and Ganora, both in the New Bethesda district of the Eastern Cape Karoo region. The fossils were recovered from an uncertain formation, possibly closely equivalent to the Balfour Formation, within the Dicynodon Assemblage Zone. Kompasia delaharpei differs from previously described early actinopterygians, including the recently described new lower Beaufort Group taxon Bethesdaichthys kitchingi, on the basis of a combination of skull and post cranial characters. The genus is characterised by: a uniquely shaped subrectangular posterior blade of the maxilla, a shortened dorsal limb of the preopercular, and a dermopterotic and dermosphenotic contacting the nasal; furthermore, the subopercular is equal to or longer than the opercular, the dorsal fin is situated in the posterior third of the body, slightly behind the position of the anal fin, and the anterior midflank scales exhibit a smooth dermal pattern or surface, with a number of faint ganoine ridges present parallel to the posterior and ventral scale margins. Kompasia appears to exhibit a relatively conservative morphology similar to that in the lower Beaufort Group taxon Bethesdaichthys kitchingi. As such, Kompasia is derived relative to stem-actinopterans such as Howqualepis, Mimia and Moythomasia, and also derived relative to earlier southern African Palaeozoic actinopterygians such as Mentzichthys jubbi and Namaichthys schroederi, but basal to stem-neopterygians such as Australosomus and Saurichthys.Item Palaeontology and geological context of a Middle Pleistocene faunal assemblage from the Gladysvale Cave, South Africa(Bernard Price Institute for Palaeontological Research, 2002) Lacruz, R S; Brink, James S; Hancox, P J; Skinner, A R; Herries, A; Schmid, Peter; Berger, Lee RPalaeontological and geological research at the Gladysvale Cave during the last decade has concentrated on de-roofed deposits located outside the Main Chamber. This area has been termed the Gladysvale External Deposit (GVED) and consists of fossil-rich calcified and decalcified sediments. Here we report on the recent analysis of both the faunal material and the geological context of this deposit. The faunal assemblage, excavated from the decalcified sediments contains 29 mammal species including taxa rare or absent in the Witwatersrand Plio-Pleistocene fossil record (e.g. Pelorovis and Kobus leche). Carnivores and porcupines are identified as accumulating agents of the bones. No new hominin findings can be reported from this deposit, and no cultural remains have been recovered. Geologically the calcified and decalcified breccias represent part of a large talus cone that is relatively unexposed. Uniquely for a cave fill in the Witwatersrand hominin-bearing sites, the sediments are horizontally stratified and form a number of flowstone bound sequences. The dating of the in situ cemented sediments is based on electron spin resonance (ESR) and palaeomagnetism. Recent results indicate that the deposits are of Middle-Pleistocene age.Item Palaeozoic insects of southern Africa: a review(Bernard Price Institute for Palaeontological Research, 2002) Geertsema, H.; van Dijk, D. E.; van den Heever, J. A.Although a substantial number of Triassic insect fossils have been discovered in southern Africa, relatively few insect fossils are known from the Permian deposits of this region. Fossil insects from the Permian period elsewhere, including the extensive entomological fauna from Eastern Europe (including Russia), Brazil and Australia is well-documented. The Irati Formation in the Parana Basin of Brazil, the temporal and lithological correlate of the Permian Whitehill Formation of South Africa, has yielded fossil insects belonging to Homoptera, N europtera, Coleoptera and Mecoptera. Fossil insects from the Whitehill Formation are usually poorly preserved and only seven specimens are mentioned in the literature. An overview is given of the more recent discoveries of Permian fossil insects in South Africa. This includes the discovery of the oldest beetle in Africa, the oldest longhorned grasshopper in the Southern Hemisphere and a survey of the Permian insects from the Beaufort Group of Natal. Reasons for the paucity of Permian insects are briefly discussed.Item Palaeozoic insects of southern Africa: a review(Bernard Price Institute for Palaeontological Research, 2002) Geertsema, H; Van Dijk, D E; Van den Heever, J AAlthough a substantial number of Triassic insect fossils have been discovered in southern Africa, relatively few insect fossils are known from the Permian deposits of this region. Fossil insects from the Permian period elsewhere, including the extensive entomological fauna from Eastern Europe (including Russia), Brazil and Australia is well-documented. The Irati Formation in the Parana Basin of Brazil, the temporal and lithological correlate of the Permian Whitehill Formation of South Africa, has yielded fossil insects belonging to Homoptera, N europtera, Coleoptera and Mecoptera. Fossil insects from the Whitehill Formation are usually poorly preserved and only seven specimens are mentioned in the literature. An overview is given of the more recent discoveries of Permian fossil insects in South Africa. This includes the discovery of the oldest beetle in Africa, the oldest longhorned grasshopper in the Southern Hemisphere and a survey of the Permian insects from the Beaufort Group of Natal. Reasons for the paucity of Permian insects are briefly discussed.Item Permian trace fossils attributed to tetrapods (Tierberg Formation, Karoo Basin, South Africa)(Bernard Price Institute for Palaeontological Research, 2002) van Dijk, D. E.; Channing, A.; van den Heever, J. A.The discovery of a paving slab with a number of prints suggestive of footprints of tetrapods led to a reinvestigation of a trace fossil, known from three localities, of which only two photographs had been published, each with only four prints. The slab was traced to a previously unrecorded site, De Puts, near Calvinia, located in the Tierberg Formation of the Ecca Group of the Karoo Supergroup. The prints from all the sites are referred to Broomichnium permianum Kuhn 1958, of which Quadrispinichna parvia of Anderson 1974 is a synonym.Item Permian trace fossils attributed to tetrapods (Tierberg Formation, Karoo Basin, South Africa)(Bernard Price Institute for Palaeontological Research, 2002) van Dijk, D E; Channing, A; van den Heever, J AThe discovery of a paving slab with a number of prints suggestive of footprints of tetrapods led to a reinvestigation of a trace fossil, known from three localities, of which only two photographs had been published, each with only four prints. The slab was traced to a previously unrecorded site, De Puts, near Calvinia, located in the Tierberg Formation of the Ecca Group of the Karoo Supergroup. The prints from all the sites are referred to Broomichnium permianum Kuhn 1958, of which Quadrispinichna parvia of Anderson 1974 is a synonym.Item Replacement names for the therapsid genera Criocephalus Broom 1928 and Olivieria Brink 1965.(Bernard Price Institute for Palaeontological Research, 2002) Kammerer, Christian F.; Sidor, Christian A.Our knowledge of premammalian synapsid evolutionary history has benefited from over a hundred years of fossil collecting, especially within the Permo-Triassic sediments of South Africa's Beaufort Group (Rubidge 1995) and the Cis-Ural region of Eastern Europe (Ivachnenko et al. 1997). In the course of our research and discussions we have discovered several errors in the present state of non-mammalian synapsid taxonomy. Here we propose emendations concerning the genera Criocephalus Broom 1928 and Olivieria Brink 1965.