Rare helical spheroidal fossils from the Doushantuo Lagerstätte: Ediacaran animal embryos come of age? Xiao, Shuhai ; Hagadorn, James W. ; Zhou, Chuanming ; Yuan, Xunlai Abstract Publication: Geology Pub Date: February 2007 DOI: 10.1130/G23277A.1 Bibcode: 2007Geo....35..115X