%0 Journal Article
%T Dawn of diverse shelled and carbonaceous animal microfossils at ~ 571 Ma.
%A Morais L
%A Freitas BT
%A Fairchild TR
%A Clavijo Arcos RE
%A Guillong M
%A Vance D
%A de Campos MDR
%A Babinski M
%A Pereira LG
%A Leme JM
%A Boggiani PC
%A Osés GL
%A Rudnitzki ID
%A Galante D
%A Rodrigues F
%A Trindade RIF
%J Sci Rep
%V 14
%N 1
%D 2024 06 28
%M 38942912
%F 4.996
%R 10.1038/s41598-024-65671-4
%X The Ediacaran-Cambrian transition documents a critical stage in the diversification of animals. The global fossil record documents the appearance of cloudinomorphs and other shelled tubular organisms followed by non-biomineralized small carbonaceous fossils and by the highly diversified small shelly fossils between ~ 550 and 530 Ma. Here, we report diverse microfossils in thin sections and hand samples from the Ediacaran Bocaina Formation, Brazil, separated into five descriptive categories: elongate solid structures (ES); elongate filled structures (EF); two types of equidimensional structures (EQ 1 and 2) and elongate hollow structures with coiled ends (CE). These specimens, interpreted as diversified candidate metazoans, predate the latest Ediacaran biomineralized index macrofossils of the Cloudina-Corumbella-Namacalathus biozone in the overlying Tamengo Formation. Our new carbonate U-Pb ages for the Bocaina Formation, position this novel fossil record at 571 ± 9 Ma (weighted mean age). Thus, our data point to diversification of metazoans, including biomineralized specimens reminiscent of sections of cloudinids, protoconodonts, anabaritids, and hyolithids, in addition to organo-phosphatic surficial coverings of animals, demonstrably earlier than the record of the earliest known skeletonized metazoan fossils.