... guizhouensis ( Xue et al., 1992 ) and Yangtzitubus semiteres new genus and species—from lenticular cherts in the upper Doushantuo Formation in the Yangtze Gorges area. Of the two named taxa, Sinocyclocyclicus guizhouensis was previously known from the Weng'an area ( Liu et al., 2008 ). The new data extend...

... Sinocyclocyclicus guizhouensis . If S. guizhouensis is an adult form of the helical spheroidal fossils, the polar invaginations (Fig. 1Q) may represent the oral invagination and aboral attachment site that facilitates juvenile settlement; tabulae would not be expected in the helical fossils because tabula...

... here. Sinocyclocyclicus guizhouensis Xue, Tang, and Yu, 1992 , is another tube interpreted as a possible stem cnidarian (Liu et al., 2008 ), although Cunningham et al. ( 2015 ) considered it to be an alga. Some Sinocyclocyclicus (Xiao et al., 2000 , fig. 2 H, I) are morphologically similar...

..., Crassitubus costatus, and Sinocyclocyclicus guizhouensis ) have been interpreted as stem-group or even crown-group cnidarians ( Liu et al. 2008 ) although not without controversy ( Cunningham et al. 2015 ). The cylindrical or tetragonal tubular morphology of Ramitubus , coupled with the presence of cross...

... that M. longus probably was not a cyanobacterium, allying it instead with the Neoproterozoic tubular microfossil Sinocyclocyclicus guizhouensis Xue et al., 1992 , which has been interpreted as a stem-group cnidarian. Bed 3 measures approximately 15.7 m thick and consists of gray-black limestone...

... al., 2008 by curved cylindrical tube with a longitudinal ridge. Sinocyclocyclicus guizhouensis Xue et al., 1992 is most similar to M. longus except the former has greater diameter and flat cross-walls ( Xue et al., 1992 ; S. Xiao et al., 2000 ). Additionally, S. guizhouensis has at least one...

...Figure 34. Tubular microfossils. ( 1 ) Quadratitubus orbigoniatus Xue, Tang, and Yu, 1992 , emend. Liu et al., 2008 , PB202082, thin section 19CW-6-13, M44/3. ( 2 ) Possible Quadratitubus orbigoniatus , PB202083, thin section 21DC-2-36, L40/2. ( 3, 4 ) Sinocyclocyclicus guizhouensis Xue...

... bridge between Megasphaera ornata and the curved tubular fossil Sinocyclocyclicus guizhouensis , the latter of which has been interpreted as a stem-group cnidarian ( Xiao et al., 2000 ; Liu et al., 2008 ) or an anthozoan ( Chen et al., 2002 ). In this interpretation, helical structure may have...