Early Ediacaran micro- and macro-fossils from South China provide insights into post-Snowball Earth marine ecosystem

Abstract Understanding of biological and ecological dynamics after the terminal Cryogenian Marinoan glaciation remains limited because the early Ediacaran fossil record is sparse and taphonomically biased toward microfossils. Here we show an early Ediacaran fossil assemblage from the Ancangping section of South China that co-preserves micro- and macrofossils in the same strata. It contains 17 genera and 35 species of acritarchs, including three new taxa, and six forms of macroscopic carbonaceous compressions. Integrated lithostratigraphic and biostratigraphic correlation with published astrochronologic and radiometric data indirectly constrains its age to approximately 620–610 million years ago, thus predating the hitherto oldest-known macrofossil assemblage (the Lantian biota at 602 million years ago) in the Ediacaran Period. The assemblage comprises cyanobacteria, phytoplankton, benthic macroalgae, and possible metazoans, indicating the co-occurrence of benthic and planktonic organisms in the aftermath of the Snowball Earth. This finding fills a temporal gap and provides insight into early Ediacaran biological communities across the Cryogenian–Ediacaran transition.