Volume 29 1992

Permanent URI for this collection

https://wiredspace.wits.ac.za/handle/10539/15932

Browse

Browsing Volume 29 1992 by Author "Raath, Michael A"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    First record of Triassic Rhynchosauria (Reptilia: Diapsida) from the Lower Zambezi Valley, Zimbabwe
    (Bernard Price Institute for Palaeontological Research, 1992) Raath, Michael A; Oesterlen, P M; Kitching, James W
    True rhynchosaurids are described from Zimbabwe for the first time. The fossils occur as partially associated skeletons and scattered isolates in upward-fining, micaceous fluvial sandstones of the Pebbly Arkose Formation (late Triassic) in the Western Cabora Bassa Basin, Lower Zambezi Valley. On the grounds that the dentary of the Zimbabwean form possesses a row of small, conical lingual teeth in addition to a palisade row of penicillate teeth on the occlusal surface, it is concluded that the taxon present is Hyperodapedon sp., and that it is closely related to a rhynchosaurid described from Tanzania. One bone identified as a prosauropod dinosaurian femur was found associated with the Zimbabwean rhynchosaurids. The late Triassic age suggested by the presence of advanced rhynchosaurids is supported by the occurrence of the typical Triassic fossil plant genus Dicroidium, and by the general stratigraphy of the beds which contain the fossils (i.e. the fossil-bearing beds are underlain by beds of mid-Triassic age or younger, and are overlain by beds of latest Triassic or early Jurassic age)
  • Thumbnail Image
    Item
    Preparation of fossil bone for histological examination
    (Bernard Price Institute for Palaeontological Research, 1992) Chinsamy, Anusuya; Raath, Michael A
    Palaeo-histology is the branch of palaeontology concerned with the microscopic structure of fossil bone. Researchers entering the field for the first time become aware of a need for a concise description of a technique to prepare thin sections from fossil bone. This note aims to fill that need by describing the procedure used in a recent palaeohistological study (Chinsamy 1988, 1990, 1991, 1992). The technique described has been successfully applied to the bones of dinosaurs and mammal-like reptiles, as well as to archaeological samples ofhuman bone and also to defatted bone of recent taxa. There is no one 'correct' method of making sections of hard tissues like bones, but all existing techniques share a number of core processes in common (Enlow 1954; Enlow and Brown 1956; Honjo and Fischer 1965; Peabody 1961 ; Macfall and Wollin 1972; Buffrenil, Ricqles, Ray and Domning 1990). Although the method described here is specifically intended for use on bone, thin sections of fossilised wood have also been obtained using the same method.