中国科学院南京地质古生物研究所机构知识库

We report the preservation of the eight-armed Ediacara fossil Eoandromeda octobrachiata as carbonaceous compressions in the Doushantuo black shale of south China and as casts and molds in the Rawnsley Quartzite in South Australia. The contrasting preservational styles in two taphonomic windows indicate that E. octobrachiata may have had a relatively recalcitrant organic integument, which rules out its close comparison with giant agglutinated foraminifers such as xenophyophores. Its octaradial symmetry and dextrally spiraling arms suggest that it may be a diploblastic-grade animal sharing some features with cnidarians and ctenophores, although its phylogenetic affinity remains open. It is the first and only unambiguously identified Ediacaran macrofossil that occurs in two drastically different taphonomic windows, thus bridging the conventional biological and taxonomic gaps between the Ediacara and Miaohe biotas, which collectively record the earliest known macroscopic and complex life.