In situ filamentous communities from the Ediacaran (approx. 563 Ma) of Brazil

Autor(es)

Becker-Kerber, Bruno ^{[1, 2]} ; Barea de Barros, Gabriel Eduardo ^[3] ; Gomes Paim, Paulo Sergio ^[4] ; Prado, Gustavo M. E. M. ^[5] ; Zucatti da Rosa, Ana Lucia ^[6] ; El Albani, Abderrazak ^[2] ; Laflamme, Marc ^[7]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Programa Posgrad Ecol & Recursos Nat, Washington Luiz 325 Km, BR-13565905 Sao Carlos, SP - Brazil

^[2] Univ Poitiers, Ctr Natl Rech Sci CNRS, Unite Mixte Rech UMR, IC2MP 7285, F-86073 Poitiers - France

^[3] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto FF, Dept Biol, Programa Posgrad Biol Comparada, Ave Bandeirantes 3900, Vila Monte Alegre, BR-14049900 Ribeirao Preto, SP - Brazil

^[4] Univ Vale Rio dos Sinos, Programa Pas Grad Geol, BR-93022750 Sao Leopoldo, RS - Brazil

^[5] Univ Sao Paulo, Inst Geociencias, Programa Pos Grad Geoquim & Geotecton, Ave Bandeirantes 3900, Vila Monte Alegre, BR-14049900 Ribeirao Preto, SP - Brazil

^[6] Petrobras SA, Santos, SP - Brazil

^[7] Univ Toronto Mississauga, Dept Chem & Phys Sci, 3359 Mississauga Rd, Mississauga, ON L5L 1C6 - Canada

• Tipo de documento: Artigo Científico
• Fonte: PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES; v. 288, n. 1942 JAN 13 2021.
• Citações Web of Science: 0

Resumo

Precambrian filamentous microfossils are common and diverse. Nevertheless, their taxonomic assignment can be difficult owing to their overall simple shapes typically lacking in diagnostic features. Here, we report in situ communities of well-preserved, large filamentous impressions from the Ediacaran Itajai Basin (ca 563 Ma) of Brazil. The filaments are uniserial (unbranched) and can reach up to 200 mu m in width and up to 44 mm in length. They occur as both densely packed or sparsely populated surfaces, and typically show a consistent orientation. Although simple in shape, their preferred orientation suggests they were tethered to the seafloor, and their overall flexibility (e.g. bent, folded and twisted) supports a biological (rather than sedimentary) affinity. Biometric comparisons with modern filamentous groups further support their biological affinity, suggesting links with either large sulfide-oxidizing bacteria (SOB) or eukaryotes. Other morphological and palaeoecological characteristics further corroborates their similarities with modern large filamentous SOB. Their widespread occurrence and association with complex Ediacaran macrobiota (e.g. frondose organisms, Palaeopascichnus) suggest that they probably played an important role in the ecological dynamics of these early benthic communities by providing firm substrates for metazoans to inhabit. It is further hypothesized that the dynamic redox condition in the latest Ediacaran, with the non-continuous rise in oxygen concentration and periods of hypoxia, may have created ideal conditions for SOB to thrive. (AU)

• Processo FAPESP: 18/21886-0 - O alvorecer de ecossistemas complexos: desvendando e comparando aspectos de preservação excepcional entre as paleobiotas de Itajaí (Ediacarano, Brasil) e Francevillian (Paleoproterozóico, Gabão)
• Beneficiário: Bruno Becker Kerber
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado