Volume 19 1976
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Browsing Volume 19 1976 by Author "Erasmus, T."
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Item A new species of Dammaroxylon Schultze-Motel, D. Natalense sp. nov. from the Cretaceous of Natal, South Africa(Bernard Price Institute for Palaeontological Research, 1976) Erasmus, T.In the Cretaceous rocks of the M'hlosinga district, Zululand, Natal a new species of the form genus Dammaroxylon Schultze-Motel, D. natalense sp. nov., has been discovered. New evidence regarding the structure of the marginal ray parenchyma cells has been obtained. The conclusion is reached that Dammaroxylon could possibly take an intermediate phylogenetic position between the Araucariaceae and Podocarpaceae.Item On tile anatomy of Dadoxylon arberi Seward with some remarks on the phylogenetical tendencies of its tracheid pits(Bernard Price Institute for Palaeontological Research, 1976) Erasmus, T.A well preserved specimen of Dadoxylon arberi Seward has been discovered in the Beaufort Series (Upper Karroo System) of the Empangeni district in Natal, South Africa. The species is characterized by the tracheid pits which are araucaroid in the multiseriate condition, but which are more often circular and separately arranged or appear in stellate groups. The cross field pits tend to be aligned in horizontal pairs. Dadoxylon arberi shows a relationship with several species of the recent Araucariaceae. Its resemblance to other Gondwana woods from other Southern Hemisphere countries suggests a great uniformity in the elements of the coniferous flora of that time. It is suggested that Dadoxylon arberi represents an intermediate form between the Araucariaceae and Podocarpaceae. The reduction in the seriation of the tracheid pits and a drifting thereof seems to stand in close correlation with the formation of annual rings.