The missing mats: MISS diversity and influence on life preservation in the late Ediacaran of the Tandilia System, Argentina

Author(s)

María Julia Arrouy ^[1] ; Lucas Veríssimo Warren ^[2] ; Fernanda Quaglio ^[3] ; Lucía Gómez-Peral ^[4] ; Lucas Inglez ^[5] ; Victoria Penzo ^[6] ; Marcello Guimarães Simões ^[7] ; Daniel Gustavo Poiré ^[8]

Affiliation

^[1] Instituto de Hidrología de Llanuras “Dr. Eduardo Jorge Usunoff” - Argentina

^[2] Universidade Estadual Paulista “Júlio de Mesquita Filho”. Instituto de Geociências e Ciências Exatas. Departamento de Geologia - Brasil

^[3] Universidade Federal de São Paulo. Departamento de Ecologia e Biologia Evolutiva - Brasil

^[4] Centro de Investigaciones Geológicas - Argentina

^[5] Universidade Estadual Paulista “Júlio de Mesquita Filho”. Instituto de Geociências e Ciências Exatas. Departamento de Geologia - Brasil

^[6] Centro de Investigaciones Geológicas - Argentina

^[7] Universidade Estadual Paulista “Júlio de Mesquita Filho”. Instituto de Biociências. Departamento de Zoologia - Brasil

^[8] Centro de Investigaciones Geológicas - Argentina

• Document type: Journal article
• Source: BRAZILIAN JOURNAL OF GEOLOGY; v. 53, n. 2 2023-08-14.

Abstract

Abstract The terminal Ediacaran fossil record includes microbial mats and body fossils characterized by simple morphologies, which represents a challenge to understand several aspects related to the paleoecology of the emerging complex life. The marine siliciclastic deposits of the Cerro Negro Formation (~560–550 Ma) contain evidence of different styles of microbially induced sedimentary structures (MISS) and discoidal forms associated with them. Different types of MISS, such as Kinneyia and wrinkle structures, elephant skin, and Arumberia, are reported and related to shallow marine depositional environments. These morphologies are commonly associated with the high quality of preservation of body fossils in Ediacaran deposits. The preservation of Aspidella discoidal holdfast is related to biotic and abiotic processes involving substrate sealing by microbial mats, fluidization, and probably organic matter decay. Both abiotic factors (tidal currents and waves, added to liquefaction and sand injection) and biotic factors (substrate biostabilization by microbial mats favoring sediment cohesion) are considered the main ones responsible for the preservation style in the Cerro Negro Formation. This formation constitutes a remarkable example in SW-Gondwana of how preservation dynamics took place on a seabed sealed by microbial mats and is an important deposit conserving diverse Ediacaran forms of life in South America. (AU)

• FAPESP's process: 15/24608-3 - Multi-proxy analysis of the Cerro Negro formation, Argentina: bioestratigraphy and paleoenvironment of the first Ediacaran fossillagerstätte in South America
• Grantee: Lucas Verissimo Warren
• Support Opportunities: Regular Research Grants