Paleobiology of the Itajaí Basin (Ediacaran, Santa Catarina, Brazil): evolutionary, paleoecological and taphonomical implications

• Main Author: Becker Kerber, Bruno
• Other Authors: Pacheco, Mírian Liza Alves Forancelli, http://lattes.cnpq.br/3481327026891705, Paim, Paulo Sergio Gomes, http://lattes.cnpq.br/8591350653509881, http://lattes.cnpq.br/4211450630568081
• Format: Thesis
• Language: English
• Published: Universidade Federal de São Carlos 2020
• Subjects: Assembleia Avalon; Biota Ediacarana; Fósseis Discoides; Pseudofósseis; Estruturas Sedimentares Microbialmente Induzidas (MISS); Tafonomia; Autigênese de Argila; Ilita; Avalon Assemblage; Ediacaran Biota; Discoidal Fossils; Pseudofossils; Microbially Induced Sedimentary Structures (MISS); Taphonomy; Clay authigenesis; Illite; CIENCIAS BIOLOGICAS::ZOOLOGIA::PALEOZOOLOGIA; White Sea
• Online Access: https://repositorio.ufscar.br/handle/ufscar/13023

New studies on the geologic history of Earth are increasingly revealing the complex relationships among evolutionary patterns, diversification of major groups, and environmental changes. In the fossil record of the Ediacaran Period (635–541 Ma), the appearance of macroscopically complex organisms and animals resulted in major modifications in the environment, setting the stage for the subsequent “Cambrian explosion” and the development of Phanerozoic-style ecosystems. The Ediacaran biota can be found in several localities throughout the world, and researchers on this subject are able now to divide it in mainly three Assemblages: Avalon, White Sea and Nama. Compared to other deposits around the world, studies on South American Ediacaran fossils are still in their early stages, but already show a great potential to understand the evolution of early complex life. In this context, this work aimed to investigate the taxonomy, taphonomy and age of the poorly known fossils from the Itajaí Basin (Santa Catarina, southern Brazil), as well as its relationships to other coeval fossiliferous strata. For that, a multi-approach investigation was conducted, using diverse techniques, such as: stereomicroscopic investigation; petrography; U/Pb radiometric dating (SHRIMP); scanning electron microscopy (SEM) and dispersive energy spectroscopy (EDS); computerized microtomography (µCT); and Raman and infrared spectroscopy. The results of this work are presented here in three main published and/or submitted articles regarding: [I] the description of the Itajaí Biota and its age; [II] the taphonomic characteristics of the ‘Ediacaran-style’ preservation at the Itajaí Basin; and [III] the nature of microbial filaments. In Article 1, it is reported the presence of Ediacaran soft-bodied organisms, such as Palaeopascichnus, discoidal forms (Aspidella and Nimbia), as well as abundant microbial mat features (e.g., reticulated tufts, Arumberia, and wrinkles). Moreover, the age of the Itajaí Basin is further constrained by U/Pb radiometric ...