The Ediacaran fossil Eoandromeda octobrachiata had a high conical body with eight arms in helicospiral arrangement along the flanks. The arms carried transverse bands proposed to be homologous to ctenophore ctenes (comb plates). Eoandromeda is interpreted as an early stem-group ctenophore, characterized by the synapomorphies ctenes, comb rows, and octoradial symmetry but lacking crown-group synapomorphies such as tentacles, statoliths, polar fields, and biradial symmetry. It probably had a pelagic mode of life. The early appearance in the fossil record of octoradial ctenophores is most consistent with the Planulozoa hypothesis (Ctenophora is the sister group of Cnidaria + Bilateria) of metazoan phylogeny.

No abstract

Forty-two conodont species belonging to 26 genera, which span the middle Darriwilian to the earliest Sandbian interval, are documented from the Wolonggang and Hatuke Creek sections in the Wuhai area of Inner Mongolia, North China. This conodont fauna is dominated by cosmopolitan and widespread species and accompanied by several endemic taxa. Four conodont zones, the Dzikodus tablepointensis, Eoplacognathus suecicus, Pygodus serra, and P. anserinus Zones, and three subzones, the Pygodus lunnensis, P. anitae, and Yangtzeplacognathus foliaceus Subzones, are recognized. Because of its slope habitat, the conodont fauna of Wuhai area differs from the coeval faunas on the North China Platform, which reflect a shallower and warmer water environment, but is similar to the contemporaneous faunas in Baltoscandia, South China, and Tarim. Moreover, the studied sections share several stratigraphically diagnostic taxa with the counterparts of the North China Platform and Western Newfoundland, which makes it an effective link for biostratigraphic correlations both regionally and internationally. The stratigraphically regular occurrences of Spinodus spinatus, a good index of a deep-water environment, represent a Spinodus biofacies that agrees with the Ordovician paleo-tectonic regimes of North China.

The abundance and diversity of macrofossils in the Ediacaran have attracted much attention. The upper Doushantuo macrobiotas in South China, including the Miaohe biota from Hubei and the Wenghui biota from Guizhou, are mainly preserved as the carbonaceous compressions and dominated by macroscopic algae and metazoans. Here, we describe 10 genera and 10 species (including 6 new genera and species) of macrofossils from the Wenghui biota. At present, the Wenghui biota yields macrofossils in more than 31 genera and 33 species, excluding those given no image and established on a few unascertained specimens. Based on the occurrence and distribution of macrofossils in both Miaohe and Wenghui areas, the middle‐late Ediacaran (back shales of the upper Doushantuo Formation) in South China can be subdivided into two assemblage biozones in biostratigraphy: (i) the Protoconites–Linbotulitaenia–Eoandromeda–Anomalophton assemblage biozone characterized by abundant and diverse macrofossils and by the ranges of Protoconites, Linbotulitaenia and Anomalophton; and (ii) the Baculiphyca–Gesinella–Cucullus–Beltanelliformis assemblage biozone characterized by the acme of the longer macrofossils Baculiphyca and Gesinella, and by few shorter and discoidal macrofossils.

No abstract