Ediacaran Assemblages Research Articles

Bioturbation structures from the middle proterozoic Narji Formation, Kurnool Group, Andhra Pradesh, India

Bioturbation structures in the form of worm burrows are reported for the first time from the Middle Proterozoic Narji Formation belonging to the Kurnool Group in Andhra Pradesh, India. The structures are tentatively classified as belonging to the Skolithos and Glossifungites assemblages ( Seilacher, 1967). Although the above assemblages are usually restricted to rocky and sandy shores, their presence in the Narji Formation, consisting dominantly of dark, pyrite-bearing limestones of euxinic, quiet-water facies, indicates that these burrows have a much wider environmental distribution. Further presence of burrows in the Middle Proterozoic Narji Formation adds yet another instance to the growing record of Precambrian trace fossils. Existence of these burrows further corroborates that diverse body fossils and ichnofossils of the Ediacaran assemblage (700 m.y.) are preceded by the evolution of simpler, and probably smaller, soft-bodied metazoans.

Bioturbation and the origin of the metazoans: Evidence from the Belt Supergroup, Montana

Research Article| September 01, 1976 Bioturbation and the origin of the metazoans: Evidence from the Belt Supergroup, Montana Charles W. Byers Charles W. Byers 1Department of Geology and Geophysics, University of Wisconsin, Madison, Wisconsin 53706 Search for other works by this author on: GSW Google Scholar Author and Article Information Charles W. Byers 1Department of Geology and Geophysics, University of Wisconsin, Madison, Wisconsin 53706 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1976) 4 (9): 565–567. https://doi.org/10.1130/0091-7613(1976)4<565:BATOOT>2.0.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Charles W. Byers; Bioturbation and the origin of the metazoans: Evidence from the Belt Supergroup, Montana. Geology 1976;; 4 (9): 565–567. doi: https://doi.org/10.1130/0091-7613(1976)4<565:BATOOT>2.0.CO;2 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 Relatively large and diverse body fossils and traces of the Ediacaran assemblage must have been preceded by the evolution of simpler, probably smaller, metazoans. The ancestral benthic burrowing metazoans may not have been fossilized but should be recognizable by bioturbate fabric in the mud they inhabited. An examination of the shale of the 1.3-eon (1.3 × 109 yr)-old Belt Supergroup disclosed no hint of biologic reworking, indicating either that the Belt basin was a large anaerobic seaway or that Belt sedimentation predated the evolution of burrowing metazoans. The lack of bioturbation, even in what were probably shallow shelf environments, supports the latter conclusion that metazoans capable of bioturbation evolved later than 1.3 eons B.P. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.