Huainan Biota

Fossils of the Huainan biota were found in the Liulaobei Formation in the lower part of the Sinian Huainan Group below Bagong Hill, Huainan, Anhui Province. The biota lived 750–800 million years ago. The biota is characterised by animals with no hard shells; hence, the fossils are mostly preserved prints and traces of activity of soft animals, mainly combinations of worms, desmids and acritarch micro-plants. A notable characteristic of the Huainan fauna is that although many types of metazoans had appeared by that time, these animals have only primary features in terms of quantity, geographic distribution and the structure of the organisms. The discovery of these fossils was significant because it indicated that the earliest metazoans were naked and that their bodies had not developed the ability to build hard shells or bones through secretion (Fig. 26).

Fig. 26

Huainan biota