Search for dissertations about: "acritarch"

Found 4 swedish dissertations containing the word acritarch.

  2. 1. Cambro-Ordovician microorganisms: acritarchs and endoliths

    Author : Martin Stockfors; Malgorzata Vidal-Moczydlowska; John S. Peel; Kenneth John Dorning; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; Cambrian; Ordovician; acritarch; endolith; Kolguev Island; North Greenland; Stratigraphy; Geovetenskap; Earth sciences; Geovetenskap;

    Abstract : Organic-walled microfossils are abundant and taxonomically diverse in Cambrian-Ordovician strata; some are important for biostratigraphy and for the correlation of geological successions. New assemblages of Cambrian-Ordovician acritarchs from Kolguev Island, Arctic Russia and Middle Cambrian ichnofossils of endoliths from Peary Land, North Greenland are studied. READ MORE

  4. 2. The Ediacaran Diversification of Organic-walled Microbiota : Ocean Life 600 Million Years Ago

    Author : Sebastian Willman; Małgorzata Moczydłowska-Vidal; John Peel; Shuhai Xiao; Uppsala universitet; []
    Keywords : Earth sciences; acritarchs; Ediacaran; Australia; biostratigraphy; microfossils; Geovetenskap;

    Abstract : The only direct evidence of past life is provided by fossils. Fossils tell us about the evolution of life on Earth and they give us clues concerning ancient environments. The Ediacaran Period (roughly 635-542 million years ago) is characterised by the appearance and diversification of various microbiota and also the diversification of metazoans. READ MORE

  5. 3. Unlocking the hidden diversity of organic-walled microfossils from the early Cambrian of North Greenland

    Author : Elise Wallet; Sebastian Willman; Ben Slater; Graham Budd; Charles H. Wellman; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Cambrian; acritarchs; organic-walled microfossils; small carbonaceous fossils; Greenland; diversity; disparity; taxonomy; taphonomy; Crustacea; plankton; Historical Geology and Paleontology; Historisk geologi och paleontologi;

    Abstract : The early Cambrian Buen Formation of North Greenland is celebrated for hosting one of the oldest Cambrian Burgess Shale-type deposits known to date – the Sirius Passet Lagerstätte. Further south in a shallower shelf facies belt, the Buen Formation yielded organic-walled microfossils (OWMs) that were originally described with a focus on acritarchs. READ MORE

  6. 4. Neoproterozoic-Early Cambrian organic-walled microfossils : Ultrastructural and biogeochemical search for their affinities

    Author : Nina M. Talyzina; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; Geovetenskap; Earth sciences; Geovetenskap; Historical Geology and Paleontology; historisk geologi och paleontologi;

    Abstract : The Neoproterozoic-Cambrian transition is marked by conspicuous radiation of skeletal fauna comparable to modern invertebrates. Phylogenetic relationships of living organisms, based on their genetic and ultrastructural complexity, suggest that most prokaryotic and protistan organisms should have evolved by the time of origination of coelomate organisms. READ MORE