The terminal Ediacaran Tongshan Lagerstätte from South China

TL;DR

The Tongshan Lagerstätte in South China reveals exceptionally preserved Ediacaran fossils, offering new insights into early marine biodiversity.

Contribution

This study reports the first known rangeomorph fronds with Burgess Shale-type preservation from the Ediacaran period.

Findings

The Tongshan Lagerstätte contains a high diversity of organisms preserved with Burgess Shale-type preservation.

Evidence suggests rapid burial and early diagenetic mineralization led to exceptional preservation of fossils.

The findings bridge the gap between different types of Ediacaran fossil preservation.

Abstract

Because the informative Burgess Shale-type preservation is uncommon in the Ediacaran, mouldic Ediacara-type preservation provides insight into the early evolution of organisms like metazoans (including typical fronds), protists, and algae. Here, we report the Burgess Shale-type preservation from the new Tongshan Lagerstätte ( ~ 551–543.74 ± 0.87 Ma), in carbonaceous mudstones/shales of the terminal Ediacaran Dengying Formation in Tongshan, Hubei, South China. The preservation of a high diversity of organisms indicates rapid, likely in situ burial in the marine photic zone below the storm wave base, revealing deep-water biodiversity coeval with the Nama Assemblage of Ediacara Biota. These are the first records, to our knowledge, of typical Ediacaran rangeomorph fronds with Burgess Shale-type preservation. The presence of Burgess Shale-type preservation of fronds reflects the rarity of fine-grained deposits in the Ediacaran Period and bridges an important gap between traditional Ediacara-type preservation, Ediacara-type preservation with organic remains, and Burgess Shale-type preservation.

Here, the authors present Ediacaran fossils from the Tongshan Lagerstätte (South China), including Burgess Shale-type rangeomorphs preserved both with fronds and holdfasts. They use sedimentary and chemical evidence to suggest that fast burial and early diagenetic mineralization produced excellent preservation.

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