Potential Ediacaran sponge gemmules from the Yangtze Gorges area in South China

Sponges are widely viewed as the most primitive metazoans. Sponge gemmule-like structures have been recovered from the lower part of the Doushantuo Formation in the Yangtze Gbrges area (South China), that were deposited between 635 and 580 Ma. Gemmosclere-like structures are embedded in the outer coat of the sponge structures. Electron probe microanalyses (EPMA) of the gemmoscleresindicate that they have siliceous composition. The naked subspheroidal sponge structures are composed of three layers, consistent with the preservation of a tri-layered theca embedded with the gemmosclere-like structures. The potential fossils of the Ediacaran sponge gemmules in the Doushantuo Formation may provide one of the earliest records of sponges. (C) 2014 International Association for Gondwana Research. Published-by Elsevier B.V. All rights reserved.