Sökning: "Historical geology and palaeontology"

Visar resultat 1 - 5 av 16 avhandlingar innehållade orden Historical geology and palaeontology.

  1. 1. The morphology and evolutionary significance of the anomalocaridids

    Författare :Allison Daley; Graham E. Budd; Nigel C. Hughes; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; anomalocaridids; Cambrian; Burgess Shale; exceptional preservation; palaeontology; Historical geology and palaeontology; Historisk geologi och paleontologi; Historical Geology and Paleontology; Historisk geologi och paleontologi;

    Sammanfattning : Approximately 600 to 500 million years ago, a major evolutionary radiation called the “Cambrian Explosion” gave rise to nearly all of the major animal phyla known today. This radiation is recorded by various fossil lagerstätten, such as the Burgess Shale in Canada, where soft-bodied animals are preserved in exquisite detail. LÄS MER

  3. 2. Origin and Lifestyles of early Brachiopods and other Lophotrochozoans : Insights from the Chengjiang and Guanshan Fossil-Lagerstätten

    Författare :Haizhou Wang; Lars E. Holmer; Zhifei Zhang; Michael Streng; David A.T. Harper; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Cambrian Explosion; Chengjiang; Guanshan; Lagerstätten; Lophotrochozoa; Brachiopoda; Earth Science with specialization in Historical Geology and Palaeontology; Geovetenskap med inriktning mot historisk geologi och paleontologi;

    Sammanfattning : One of the great unsolved evolutionary questions concerns the origin and phylogeny of the major animal phyla that appeared in the fossil record more than 540 million years ago, during the Cambrian explosion. Although new molecular information has been very useful, we still have little understanding about the origin of most of the phyla of bilaterians living today. LÄS MER

  4. 3. Evolution and taxonomy of Cambrian arthropods from Greenland and Sweden

    Författare :Martin Stein; John S. Peel; Dieter Waloszek; David J. Siveter; Reinhardt M. Kristensen; David L. Bruton; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Cambrian; Arthropods; Trilobites; Evolution; Greenland; Sweden; Historical geology and palaeontology; Historisk geologi och paleontologi;

    Sammanfattning : Arthropods have a rich fossil record spanning the Phanerozoic. Biomineralized forms such as the extinct trilobites are particularly common and are proven index fossils for biostratigraphy. Forms with an unmineralized cuticle are more rare, preserved only in so called konservat lagerstätten. LÄS MER

  5. 4. Exceptionally Preserved Cambrian Lophotrochozoa : Taxonomy, Systematics and Taphonomy of Chengjiang and Indian Springs Lophophorates

    Författare :Aodhán D. Butler; Michael Streng; Lars E. Holmer; Christian Skovsted; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Brachiopoda; Chengjiang; Lagerstätte; Cambrian Explosion; palaeobiology; stem-group; entoproct; phoronid; tommotiid; exceptional preservation.; Earth Science with specialization in Historical Geology and Palaeontology; Geovetenskap med inriktning mot historisk geologi och paleontologi;

    Sammanfattning : The origin and evolution of Lophotrochozoa can be traced to the plethora of lower Cambrian scleritome taxa.  We aim to determine the character suites linking these stem-Lophotrochozoa to their extant crown relatives, in particular the small shelly tommotiids and the stem-group brachiopods. LÄS MER

  7. 5. Early Cambrian Problematic Lophotrochozoans and Dilemmas of Scleritome Reconstructions

    Författare :Cecilia M Larsson; Lars E Holmer; Christian B Skovsted; Anette E S Högström; John S Peel; Glenn A Brock; Michael J Vendrasco; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Problematica; scleritome; Trachyplax; tommotiid; Cambrian; South Australia; North Greenland; Earth Science with specialization in Historical Geology and Palaeontology; Geovetenskap med inriktning mot historisk geologi och paleontologi;

    Sammanfattning : The emergence and radiation of metazoan body plans around the Precambrian/Cambrian boundary, some 500-600 million years ago, seems to be concordant with the appearance and diversification of preservable hard parts. Several Precambrian soft-bodied, multicellular organisms most likely represent stem-group bilaterians, but their fossil record is rather sparse. LÄS MER