TY - JOUR
T1 - The 2.1 Ga old Francevillian biota
T2 - Biogenicity, taphonomy and biodiversity
AU - El Albani, Abderrazak
AU - Bengtson, Stefan
AU - Canfield, Donald E.
AU - Riboulleau, Armelle
AU - Bard, Claire Rollion
AU - Macchiarelli, Roberto
AU - Pemba, Lauriss Ngombi
AU - Hammarlund, Emma
AU - Meunier, Alain
AU - Mouele, Idalina Moubiya
AU - Benzerara, Karim
AU - Bernard, Sylvain
AU - Boulvais, Philippe
AU - Chaussidon, Marc
AU - Cesari, Christian
AU - Fontaine, Claude
AU - Chi-Fru, Ernest
AU - Ruiz, Juan Manuel Garcia
AU - Gauthier-Lafaye, François
AU - Mazurier, Arnaud
AU - Pierson-Wickmann, Anne Catherine
AU - Rouxel, Olivier
AU - Trentesaux, Alain
AU - Vecoli, Marco
AU - Versteegh, Gerard J.M.
AU - White, Lee
AU - Whitehouse, Martin
AU - Bekker, Andrey
PY - 2014/6/25
Y1 - 2014/6/25
N2 - The Paleoproterozoic Era witnessed crucial steps in the evolution of Earth's surface environments following the first appreciable rise of free atmospheric oxygen concentrations ∼2.3 to 2.1 Ga ago, and concomitant shallow ocean oxygenation. While most sedimentary successions deposited during this time interval have experienced thermal overprinting from burial diagenesis and metamorphism, the ca. 2.1 Ga black shales of the Francevillian B Formation (FB2) cropping out in southeastern Gabon have not. The Francevillian Formation contains centimeter-sized structures interpreted as organized and spatially discrete populations of colonial organisms living in an oxygenated marine ecosystem. Here, new material from the FB2 black shales is presented and analyzed to further explore its biogenicity and taphonomy. Our extended record comprises variably sized, shaped, and structured pyritized macrofossils of lobate, elongated, and rodshaped morphologies as well as abundant non-pyritized disk-shaped macrofossils and organic-walled acritarchs. Combined microtomography, geochemistry, and sedimentary analysis suggest a biota fossilized during early diagenesis. The emergence of this biota follows a rise in atmospheric oxygen, which is consistent with the idea that surface oxygenation allowed the evolution and ecological expansion of complex megascopic life.
AB - The Paleoproterozoic Era witnessed crucial steps in the evolution of Earth's surface environments following the first appreciable rise of free atmospheric oxygen concentrations ∼2.3 to 2.1 Ga ago, and concomitant shallow ocean oxygenation. While most sedimentary successions deposited during this time interval have experienced thermal overprinting from burial diagenesis and metamorphism, the ca. 2.1 Ga black shales of the Francevillian B Formation (FB2) cropping out in southeastern Gabon have not. The Francevillian Formation contains centimeter-sized structures interpreted as organized and spatially discrete populations of colonial organisms living in an oxygenated marine ecosystem. Here, new material from the FB2 black shales is presented and analyzed to further explore its biogenicity and taphonomy. Our extended record comprises variably sized, shaped, and structured pyritized macrofossils of lobate, elongated, and rodshaped morphologies as well as abundant non-pyritized disk-shaped macrofossils and organic-walled acritarchs. Combined microtomography, geochemistry, and sedimentary analysis suggest a biota fossilized during early diagenesis. The emergence of this biota follows a rise in atmospheric oxygen, which is consistent with the idea that surface oxygenation allowed the evolution and ecological expansion of complex megascopic life.
UR - http://www.scopus.com/inward/record.url?scp=84903525549&partnerID=8YFLogxK
U2 - 10.1371/journal.pone.0099438
DO - 10.1371/journal.pone.0099438
M3 - Article
C2 - 24963687
AN - SCOPUS:84903525549
SN - 1932-6203
VL - 9
JO - PLoS ONE
JF - PLoS ONE
IS - 6
M1 - e99438
ER -
