2000/11/28 by Shuhai Xiao, Xunlai Yuan, Andrew H. Knoll · 5 citations
Earth and Planetary Sciences · #Marine Invertebrate Physiology and Ecology #Marine Biology and Ecology Research #Paleontology and Stratigraphy of Fossils
paper · doi:10.1073/pnas.250491697
openalex publication_date 2000/11/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/22
Phosphatic sedimentary rocks preserve a record of early animal life different from and complementary to that provided by Ediacaran fossils in terminal Proterozoic sandstones and shales. Phosphorites of the Doushantuo Formation, South China, contain eggs, egg cases, and stereoblastulae that document animals of unspecified phylogenetic position; small fossils containing putative spicules may specifically record the presence of sponges. Microfossils recently interpreted as the preserved gastrulae of cnidarian and bilaterian metazoans can alternatively be interpreted as conventional algal cysts and/or egg cases modified by diagenetic processes known to have had a pervasive influence on Doushantuo phosphorites. Regardless of this interpretation, evidence for Doushantuo eumetazoans is provided by millimeter-scale tubes that display tabulation and apical budding characteristic of some Cnidaria, especially the extinct tabulates. Like some Ediacaran remains, these small, benthic, colonial fossils may represent stem-group eumetazoans or stem-group cnidarians that lived in the late Proterozoic ocean.