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Publication - Dr John Cunningham

    Critical appraisal of tubular putative eumetazoans from the Ediacaran Weng’an Doushantuo biota


    Cunningham, JA, Vargas, KM, Pengju, L, Belivanova, V, Marone, F, Martínez-Pérez, C, Guizar-Sicairos, M, Holler, M, Bengtson, S & Donoghue, PCJ, 2015, ‘Critical appraisal of tubular putative eumetazoans from the Ediacaran Weng’an Doushantuo biota’. Proceedings of the Royal Society B: Biological Sciences, vol 282.


    Molecular clock analyses estimate that crown-group animals began
    diversifying hundreds of millions of years before the start of the
    Cambrian period. However, the fossil record has not yielded unequivocal
    evidence for animals during this interval. Some of the most promising
    candidates for Precambrian animals occur in the Weng'an biota of South
    China, including a suite of tubular fossils assigned to Sinocyclocyclicus, Ramitubus, Crassitubus and Quadratitubus,
    that have been interpreted as soft-bodied eumetazoans comparable to
    tabulate corals. Here, we present new insights into the anatomy,
    original composition and phylogenetic affinities of these taxa based on
    data from synchrotron radiation X-ray tomographic microscopy,
    ptychographic nanotomography, scanning electron microscopy and electron
    probe microanalysis. The patterns of deformation observed suggest that
    the cross walls of Sinocyclocyclicus and Quadratitubus were more rigid than those of Ramitubus and Crassitubus. Ramitubus and Crassitubus specimens preserve enigmatic cellular clusters at terminal positions in the tubes. Specimens of Sinocyclocyclicus and Ramitubus
    have biological features that might be cellular tissue or subcellular
    structures filling the spaces between the cross walls. These
    observations are incompatible with a cnidarian interpretation, in which
    the spaces between cross walls are abandoned parts of the former living
    positions of the polyp. The affinity of the Weng'an tubular fossils may
    lie within the algae.

    Full details in the University publications repository