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Nonbiomineralized carapaces in Cambrian seafloor landscapes (Sirius Passet, Greenland): Opening a new window into early Phanerozoic benthic ecology

2012; Geological Society of America; Volume: 40; Issue: 6 Linguagem: Inglês

10.1130/g32853.1

1943-2682

M. Gabriela Mángano, Richard G. Bromley, David A. T. Harper, Arne T. Nielsen, M. Paul Smith, Jakob Vinther,

Marine Biology and Ecology Research

Research Article| June 01, 2012 Nonbiomineralized carapaces in Cambrian seafloor landscapes (Sirius Passet, Greenland): Opening a new window into early Phanerozoic benthic ecology M. Gabriela Mángano; M. Gabriela Mángano * 1Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon SK S7N 5E2, Canada *E-mail: gabriela.mangano@usask.ca. Search for other works by this author on: GSW Google Scholar Richard G. Bromley; Richard G. Bromley 2Natural History Museum of Denmark (Geological Museum), University of Copenhagen, Øster Voldgade 5-7, DK-1350 Copenhagen K, Denmark Search for other works by this author on: GSW Google Scholar David A.T. Harper; David A.T. Harper 3Department of Earth Sciences, Durham University, Durham DH1 3LE, UK Search for other works by this author on: GSW Google Scholar Arne T. Nielsen; Arne T. Nielsen 2Natural History Museum of Denmark (Geological Museum), University of Copenhagen, Øster Voldgade 5-7, DK-1350 Copenhagen K, Denmark Search for other works by this author on: GSW Google Scholar M. Paul Smith; M. Paul Smith 4Oxford University Museum of Natural History, Parks Road, Oxford OX1 3PW, UK Search for other works by this author on: GSW Google Scholar Jakob Vinther Jakob Vinther 5Jackson School of Geosciences, University of Texas at Austin, 1 University Station, Austin, Texas 78712-0254, USA Search for other works by this author on: GSW Google Scholar Author and Article Information M. Gabriela Mángano * 1Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon SK S7N 5E2, Canada Richard G. Bromley 2Natural History Museum of Denmark (Geological Museum), University of Copenhagen, Øster Voldgade 5-7, DK-1350 Copenhagen K, Denmark David A.T. Harper 3Department of Earth Sciences, Durham University, Durham DH1 3LE, UK Arne T. Nielsen 2Natural History Museum of Denmark (Geological Museum), University of Copenhagen, Øster Voldgade 5-7, DK-1350 Copenhagen K, Denmark M. Paul Smith 4Oxford University Museum of Natural History, Parks Road, Oxford OX1 3PW, UK Jakob Vinther 5Jackson School of Geosciences, University of Texas at Austin, 1 University Station, Austin, Texas 78712-0254, USA *E-mail: gabriela.mangano@usask.ca. Publisher: Geological Society of America Received: 21 Sep 2011 Revision Received: 19 Dec 2011 Accepted: 10 Jan 2012 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2012 Geological Society of America Geology (2012) 40 (6): 519–522. https://doi.org/10.1130/G32853.1 Article history Received: 21 Sep 2011 Revision Received: 19 Dec 2011 Accepted: 10 Jan 2012 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation M. Gabriela Mángano, Richard G. Bromley, David A.T. Harper, Arne T. Nielsen, M. Paul Smith, Jakob Vinther; Nonbiomineralized carapaces in Cambrian seafloor landscapes (Sirius Passet, Greenland): Opening a new window into early Phanerozoic benthic ecology. Geology 2012;; 40 (6): 519–522. doi: https://doi.org/10.1130/G32853.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Widespread microbial mats and the absence of significant bioturbation resulted in a poorly developed mixed layer and extensive cohesive substrates during the Ediacaran-Cambrian transition. Large nonbiomineralized arthropod carapaces overprinted with trails, interconnected burrow systems, narrow-caliber structures with dendritic terminations, and annulated burrows are abundant in the Early Cambrian Sirius Passet Lagerstätte (Greenland). Taphonomic controls were partially responsible for the pronounced association of these structures and carapaces, but ecologic conditions are envisioned as playing a significant role. Although some trace fossils (e.g., annulated structures) may be related to scavenging and/or deposit feeding, morphologic evidence suggests that this is not always the case. Interconnected burrow systems provide evidence for re-use of structures, suggesting grazing on or farming of bacteria. Sulfur bacteria were probably abundant in Cambrian sediments, requiring a source of sulfur or sulfide and limited quantities of oxygen. Anoxic sediment provided a source of hydrogen sulfide, whereas burrow outlets connected to the oxygenated sediment-water interface. Carcasses and molds of nonbiomineralized organisms may have acted as attractors, supporting a community of small invertebrates. Carapaces created a sharp boundary, further decreasing oxygen diffusion into the sediment. This steep oxygen gradient at the organic surface of the carapace promoted the growth of sulfur bacteria that could have served as the primary food for small macrofauna and meiofauna. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.