Browsing Volume 35 1999 by Title
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ItemA dinosaur fauna from the Late Cretaceous (Cenomanian) of northern Sudan(Bernard Price Institute for Palaeontological Research, 1999) Rauhut, Oliver W MA dinosaur fauna from the Cenomanian of northern Sudan (Wadi Milk Formation) is described. It comprises at least nine, probably ten to eleven taxa: a dicraeosaurid, a titanosaurid and another undetermined sauropod (possibly a titanosaurid), two charcharodontosaurids, a dromaeosaurid, a probable hypsilophodontid and two iguanodontian ornithopods. It is one of the most diverse dinosaur faunas known from the Cretaceous of Africa. The environment was probably a semiarid savanna with some rivers, lined by dense vegetation, with abundant sauropods, less abundant theropods and rare ornithopods. Gigantic carcharodontosaurids were at the top of the food chain. At the present state of knowledge, the dinosaur fauna from the middle to late Cretaceous of Africa can be characterized by the presence of carcharodontosaurids, spinosaurids, titanosaurids, diplodocoids, and possibly iguanodontian ornithopods. ItemFurther material of the ceratosaurian dinosaur Syntarsus from the Elliot Formation (Early Jurassic) of South Africa(Bernard Price Institute for Palaeontological Research, 1999) Munyikwa, DarlingtonTwo further fossils recovered from the Elliot Formation in South Africa are referred to the ceratosaurian genus Syntarsus: a partial pelvis and a well preserved and articulated snout. The pelvic fragment consists of most of the posterior end of the left ilium and sacrum, with a small part of the right ilium attached. The acetabular area and ‘brevis shelf’ of the left ilium are well preserved, as is the ventral surface of the sacrum. These parts show features characteristic of Syntarsus material from Zimbabwe. The snout has the premaxillae, maxillae, nasals and dentaries from both sides preserved, of which only the premaxillae are more or less complete. The premaxilla has four alveoli and the maxilla nine, and the maxilla bears the characteristic dimpling on its lateral surface also seen in Syntarsus material collected in Zimbabwe. The snout also possesses the characteristic small diastema or subnarial gap between the premaxillary and maxillary teeth shown by Syntarsus material from elsewhere. The snout is strongly compressed bilaterally and the jaws are tightly closed, so that the dentary teeth are obscured beneath the upper dentition. This compression has crushed the palatal region, obscuring palatal details. ItemMid-Cretaceous (Cenomanian) snakes from Wadi Abu Hashim, Sudan: the earliest snake assemblage(Bernard Price Institute for Palaeontological Research, 1999) Rage, J C; Werner, CThe Cenomanian (mid-Cretaceous) beds at Wadi Abu Hashim (Sudan) have yielded a snake assemblage that is very rich and diverse for its geological age. It is by far the oldest known snake fauna. As the assignment of the hitherto earliest presumed snake (Barremian) to the Serpentes may now be questioned, this diverse fauna is only slightly younger than the earliest certain appearance of snakes (late Albian). The fauna is a surprising mixture of very primitive and comparatively advanced snakes. It includes two forms belonging to the lapparentophiid-grade of snakes (‘ lapparentophiid-grade snake A ’ and ‘ lapparentophiid-grade snake B ’), an indeterminate Madtsoiidae, a possible Palaeophiidae, the aniliid Coniophis dabiebus sp. nov., Coniophis cf. C. dabiebus, the nigerophiid Nubianophis afaahus gen. et sp. nov., Nubianophis cf. N. afaahus, the russellophiid Krebsophis thobanus gen. et sp. nov., a Colubroidea incertae sedis (indeterminate family), and two indeterminate snakes. In sum, at least nine species, perhaps twelve, are present. They represent at least seven families: at least one family of lapparentophiid-grade (?Lapparentophiidae), Madtsoiidae, ?Palaeophiidae, Aniliidae, Nigerophiidae, Russellophiidae, and an indeterminate colubroid family. The presence of colubroid snakes (Russellophiidae and an indeterminate family) as early as the mid-Cretaceous is especially unexpected. It may be inferred from phylogenies that the higher taxa of snakes (Anilioidea, Booidea, Acrochordoidea, Colubroidea, and obviously Scolecophidia) were already present during mid-Cretaceous times. The diversity of this fauna, coupled with the presence of advanced forms (colubroids), suggest that the origin of snakes markedly antedates the Cenomanian. Africa played an important role in the early radiation and, probably, in the origin of snakes. ItemObservations on the structure of the Early Permian reptile Stereosternum tumidum Cope(Bernard Price Institute for Palaeontological Research, 1999) Modesto, Sean PatrickNew information on the mesosaur Stereosternum tumidum is derived from a nearly complete skeleton and other material. Two autapomorphies are identified for Stereosternum: (1) presence of an ‘odontoid’ axial process, formed probably by co-ossification of the atlantal pleurocentrum to that of the axis, and (2) the presence of a posterior supraneural process on the neural arch of dorsal vertebrae. Temporal fenestration appears to be absent in Stereosternum, marginal teeth are determined to be subcircular rather than oval in cross section and in this respect resemble those of Mesosaurus, and there is no sign of fracture planes in the caudal vertebrae that could be indicative of caudal autotomy. A phylogenetic analysis, based on a slightly modified data matrix from the literature, identifies Mesosauridae as the sister group of Parareptilia within the reptilian clade Anapsida (sensu lato). As a consequence of this rearrangement of amniote tree topology, the stem-based taxon Sauropsida is regarded to be in abeyance, because it now includes exactly the same taxa as Reptilia. Mesosaurs, at more than 275 million years of age, can be recognised as the oldest known anapsid reptiles. ItemPalaeobiology of Early Carboniferous lacustrine biota of the Waaipoort Formation (Witteberg Group), South Africa(Bernard Price Institute for Palaeontological Research, 1999) Evans, F JThe Early Carboniferous (Visean) Waaipoort Formation (Cape Supergroup, Witteberg Group) is a heterolithic sandstone dominated formation containing apatite-rich and calcite-rich fossiliferous nodules. Exposures of the Waaipoort Formation (Lake Mentz Subgroup) are not common and are found within the Cape Fold Belt in the Eastern and Western Cape. Fossils in the formation include palaeoniscoid fishes, sharks, acanthodians, ichnofauna, thin-shelled unionid bivalves, two genera of plants, and a cyrtoctenid eurypterid. The salinity of the Waaipoort dual basin depository is interpreted as being fresh to brackish water with some minor fluctuations. The palaeoenvironment is interpreted as being lacustrine. ItemPermo-Triassic fossil woods from the South African Karoo Basin(Bernard Price Institute for Palaeontological Research, 1999) Bamford, Marion KThe 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. ItemPreliminary report of dinosaur tracks in Qwa Qwa, South Africa(Bernard Price Institute for Palaeontological Research, 1999) Gow, Chris E; Latimer, E MWe record the presence of tridactyl dinosaur tracks preserved on a siltstone surface in a watercourse in a north eastern Free State game park. ItemRecognition of neotype specimens for species described from the Arnot Pipe, Banke, Namaqualand, South Africa(Bernard Price Institute for Palaeontological Research, 1999) de Villiers, S EImportant palynological studies were completed by Scholtz (1985) on material from the Arnot Pipe on the farm Banke in Namaqualand, Northern Cape Province. The results comprised a rare record of early Tertiary vegetation in southern Africa. The body of Scholtz’s research consisted of systematic, descriptive palynology including the description of one new genus and fifteen new species. Ongoing research into South Africa’s Tertiary palynology requires that the type specimens from Arnot be used for comparative purposes. However, the microscope slides on which they were founded were not available for examination. Another set of slides, representing two of the seven samples taken at Arnot, was used to search for neotype specimens to replace the missing holotypes. Specimens representing all fifteen new species were found, but were often badly preserved, obscured by debris or trapped between air bubbles as the condition of the decade-old microscope slides had deteriorated. Only specimens in good condition were selected as neotypes, and comprehensively illustrated. Four of Scholtz’s new species were transferred to alternative, more applicable, genera. ItemStereospondyl amphibians from the Elliot Formation of South Africa(Bernard Price Institute for Palaeontological Research, 1999) Warren, Anne; Damiani, RossThis paper documents the first members of the Chigutisauridae (Amphibia, Stereospondyli) from southern Africa and the first post-Triassic stereospondyls from that region. The material, from the Lower and Upper Elliot Formation, was associated with a diverse fauna including early mammals and dinosaurs. Most temnospondyls known to have survived the Triassic are brachyopoids, with large members of the Chigutisauridae present in the Jurassic and Cretaceous of Gondwana, and smaller members of the Brachyopidae in the Jurassic of Eurasia. ItemTaxonomic status of the skull A.l.444-2 from the Pliocene of Hadar, Ethiopia(Bernard Price Institute for Palaeontological Research, 1999) Ferguson, Walter WA nearly complete hominid skull, A.L.444-2, from the Pliocene of Hadar in Ethiopia, has been attributed to Australopithecus afarensis Johanson, White & Coppens 1978. Comparative morphological analysis indicates that it may not conform to this species. Cranial and dental morphology and measurements of A.L.444-2 agree more closely with those of A. africanus Dart 1925, to which it could be reassigned. ItemThe Triassic reptile Palacrodon browni Broom, synonymy and a new specimen(Bernard Price Institute for Palaeontological Research, 1999) Gow, Chris EPalacrodon browni Broom 1906 (=Fremouwsaurus geludens Gow 1992) is a small enigmatic diapsid reptile from the Cynognathus Assemblage Zone of South Africa and Antarctica whose dentition is very similar to that of coeval procolophonids.