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dc.contributor.authorBamforth, Emily
dc.contributor.otherQueen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.))en
dc.date2008-07-25 11:01:43.469en
dc.date.accessioned2010-02-10T13:34:45Z
dc.date.available2010-02-10T13:34:45Z
dc.date.issued2010-02-10T13:34:45Z
dc.identifier.urihttp://hdl.handle.net/1974/5433
dc.descriptionThesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2008-07-25 11:01:43.469en
dc.description.abstractRangeomorphs are a distinct group of millimeter- to meter-scale soft-bodied macrofossils that are restricted to the latter half of the late Neoproterozoic Ediacaran Period (635Ma- 542Ma). These fossils represent an extinct higher level taxon characterized by a modular construction based on a single architectural unit: the centimeter-scale, chevron-shaped rangeomorph element which displays several orders of self-similar branching. These elements could be arranged in a variety of different ways, constituting the wide array of gross morphologies found within the Group Rangeomorpha. The largest and most diverse assemblage of rangeomorph fossils in the world is found at Mistaken Point, on the Avalon Peninsula of Newfoundland, Canada, where these organisms are preserved within their original, in situ paleocommunities. Multibranched rangeomorphs are typified by bush-, comb- and network-shaped fossils which display multiple rangeomorph-bearing structures attached to an untethered basal stolon or central attachment point. Multibranched, comb-shaped rangeomorphs are endemic to Mistaken Point, and are represented by fossils displaying multiple parallel struts emerging along one side of an elongate, curved pedicle rod. Morphological and taphonomic evidence suggests that, in life, this organism had two rows of struts, each bearing a rangeomorph frondlet, arranged in an alternating pattern along the curved, tubular pedicle rod. Biometric analyses imply that the struts were added to both ends of the pedicle rod throughout the organism’s lifetime, with later inflation of the rangeomorph frondlets. Each comb-shaped rangeomorph locality likely represents a different age cohort within the organism’s lifecycle, providing rare evidence for spatfall reproduction in Ediacarans, which is similar to that found in modern macrobenthic organisms with pelagic larvae. Network-shaped multibranched rangeomorphs, represented by symmetrical to asymmetrical net-like fossils, are also endemic to Mistaken Point. This genus is reconstructed as having a symmetrical arrangement of flexible, rangeomorph-bearing leaflets that were, in part, neutrally buoyant with respect to the seawater. This flexible leaflet structure is unique, and shared only with a rare, previously undescribed, Ediacaran frond-like organism. It is suggested that the enigmatic leaflet structures shared by these two morphologically distinct taxa represent a new type of rangeomorph branching architecture, and therefore constitute a new type of rangeomorph.en
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dc.languageenen
dc.language.isoenen
dc.relation.ispartofseriesCanadian thesesen
dc.rightsThis publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.en
dc.subjectEdiacaranen
dc.subjectPaleontologyen
dc.subjectMistaken Pointen
dc.subjectRangeomorphsen
dc.subjectNeoproterozoicen
dc.subjectPaleoecologyen
dc.titleMultibranched rangeomorphs from the Ediacaran Mistaken Point assemblage, Newfoundland, Canadaen
dc.typethesisen
dc.description.restricted-thesisThe systematic paleontology of the three new fossil genera and species described in this thesis does not constitute the official description of these taxa in accordance with the International Code of Zoological Nomenclature (third edition). Under this Code, the description of a new taxon is not considered official until the systematic paleontology has appeared in a recognized scientific publication. Previous publication in an invalid medium (e.g. a thesis or a conference abstract) would create considerable confusion that might invalidate the species name. The systematic paleontology of the two new genera described in Chapter 3 of this thesis has not yet appeared in such a scientific publication. I must therefore request that this thesis be restricted for a period of at least six months, until the paper officially describing these taxa (currently in preparation for submission to a peer-reviewed journal) has been published. Restricting the thesis will protect the unpublished data, taxonomic descriptions, and scientific names.en
dc.description.degreeMasteren
dc.contributor.supervisorNarbonne, M. Guyen
dc.contributor.departmentGeological Sciences and Geological Engineeringen


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