Morphology and systematics of fossils in the Sinian Wulingshan biota from western Hunan Province

Carbonaceous load-cast fossils found in black shale in the middle part of the late Late Sinian Li-uchapo Formation at Ligonggang,Taoyuan,western Hunan,provide a rare Burgess-Shale-type tapho-nomic window for late terminal Precambrian biology.Based on a reexamination of published and new ma-terials,the authors have recognized17distinct taxa.Most of these fossils can be interpreted as prokaryotes or multicellular algae.Phylogenetically derived coenocytic green algae or brown algae and cyanobacterium appear to be present.The discovery of Apsidium sphaericus with spherical or disc-like thalli or well-pre-served concentric folds further provide important fossil evidence that many of the simple disc-like fossils found in the Ediacara biota(or Baihai biota)are probably multicellular algae rather than jellyfish.The ap-pearance of the large-sized disc-like fossils with concentric fold structure in the Wulingshan biota and the characteristics of their associated organisms indicate that the Wulingshan biota is the product of divergence and development of the Ediacara biota and is a new Ediacara biota type characterized by the development of abundant multicellular algae in the late terminal Precambrian.