A Biofilm Channel Origin for Vermiform Microstructure in Carbonate Microbialites.

Autor: Ibarra Y; School of the Environment, San Francisco State University, San Francisco, California, USA., Marenco PJ; Department of Geology, Bryn Mawr College, Bryn Mawr, Pennsylvania, USA., Centlivre JP; School of Life Sciences, University of Nevada, Las Vegas, Nevada, USA., Hedlund BP; School of Life Sciences, University of Nevada, Las Vegas, Nevada, USA., Rademacher LK; Geological and Environmental Sciences, University of the Pacific, Stockton, California, USA., Greene SE; School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, UK., Bottjer DJ; Department of Earth Science, University of Southern California, Los Angeles, California, USA., Corsetti FA; Department of Earth Science, University of Southern California, Los Angeles, California, USA.
Jazyk: angličtina
Zdroj: Geobiology [Geobiology] 2024 Sep-Oct; Vol. 22 (5), pp. e12623.
DOI: 10.1111/gbi.12623
Abstrakt: A three-dimensional tubular fabric known as "vermiform microstructure" in Phanerozoic and Neoproterozoic carbonate microbialites has been hypothesized to represent the body fossil of nonspicular keratose demosponges. If correct, this interpretation extends the sponge body fossil record and origin of animals to ~890 Ma. However, the veracity of the keratose sponge interpretation for vermiform microstructure remains in question, and the origin of the tubular fabric is enigmatic. Here we compare exceptionally well-preserved microbialite textures from the Upper Triassic to channel networks created by modern microbial biofilms. We demonstrate that anastomosing channel networks of similar size and geometries are produced by microbial biofilms in the absence of sponges, suggesting the origin for vermiform microstructure in ancient carbonates is not unique to sponges and perhaps best interpreted conservatively as likely microbial in origin. We present a taphonomic model of early biofilm lithification in seawater with anomalously high carbonate saturation necessary to preserve delicate microbial textures. This work has implications for the understanding of three-dimensional biofilm architecture that goes beyond the current micro-scale observations available from living biofilm experiments and suggests that biofilm channel networks have an extensive fossil record.
(© 2024 John Wiley & Sons Ltd.)
Databáze: MEDLINE
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