# 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.

## Key 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.