This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: A rare assemblage of micro- and macro-fossils found in a roadside outcrop in South China, featuring thin ribbons, branching shapes and a tiny balloon on a stalk, offers a glimpse of marine life after one of Earth's most extreme ice ages. The Marinoan "Snowball Earth" glaciation ended about 635 million years ago, after ice had reached tropical oceans.
Reconstructing what the marine communities looked like in the tens of millions of years after this era remains difficult. Much of the surviving evidence is microscopic, and larger organisms are poorly represented. The newly described fossils bring both into view.
Preserved together in the same rock layers, they reveal an array of tiny drifting organisms and larger algae anchored to the seabed. Qin Ye of the China University of Geosciences in Wuhan and colleagues detail the discovery in the journal Communications Biology. The fossils' estimated age is 620 million to 610 million years.
What can this diverse little community tell us about the sparsely documented stretch of life after the ice? At Ancangping, in Hubei province's Yangtze Gorges area, different rocks preserved different original inhabitants. Microscopic remains occur inside hard nodules of chert, while larger organisms survive as flattened, carbon-rich impressions in the surrounding shale.
Finding both types of fossils together allows researchers to connect forms of life that the early fossil record usually preserves separately. The team examined hundreds of thin rock sections and fossil-bearing slabs. They identified 35 species of organic-walled microfossils called acritarchs, including three new species, alongside six broad forms of larger fossils.
The larger examples are mostly millimeter-scale. Narrow, curved ribbons dominate, accompanied by disks, tangled threads and branching shapes. One specimen resembles an elongated balloon on a stalk.
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