Publication Date:
2022-05-25
Description:
Author Posting. © The Author(s), 2013. This is the author's version of the work. It is posted here by permission of National Academy of Sciences for personal use, not for redistribution. The definitive version was published in Proceedings of the National Academy of Sciences of the United States of America 110 (2013): 9830-9834, doi:10.1073/pnas.1221721110.
Description:
Microbialites, which are organosedimentary structures formed by microbial
communities through binding and trapping and/or in situ precipitation, have a wide array of
distinctive morphologies and long geologic record. The origin of morphological variability is
hotly debated; elucidating the cause or causes of microfabric differences could provide insights
into ecosystem functioning and biogeochemistry during much of Earth’s history. Although rare
today, morphologically distinct, co-occurring extant microbialites provide the opportunity to
examine and compare microbial communities that may be responsible for establishing and
modifying microbialite microfabrics. Highborne Cay, Bahamas, has extant laminated (i.e.,
stromatolites) and clotted (i.e., thrombolites) marine microbialites in close proximity, allowing
focused questions about how community composition relates to physical attributes. Considerable
knowledge exists about prokaryotic composition of microbialite mats (i.e., stromatolitic and
thrombolitic mats) but little is known about their eukaryotic communities, especially regarding
heterotrophic taxa. Thus, the heterotrophic eukaryotic communities of Highborne stromatolites
and thrombolites were studied. Here, we show that diverse foraminiferal communities inhabit
microbialite mat surfaces and subsurfaces, thecate foraminifera are relatively abundant in all
microbialite types, especially thrombolitic mats, foraminifera stabilize grains in mats, and thecate
reticulopod activities can impact stromatolitic mat lamination. Accordingly, and in light of
foraminiferal impacts on modern microbialites, our results indicate that the microbialite fossil
record may reflect the impact of the radiation of these protists.
Description:
Collections were supported by NSF ARRA
grants OCE-0926421 (to JMB and VPE) and OCE-0926372 (to RES).
Description:
2013-11-28
Repository Name:
Woods Hole Open Access Server
Type:
Preprint
Format:
application/pdf
