Ordovician - Early Silurian (Llandovery) stratigraphy and palaeontology of the Upper Yangtze platform, South China post-conference field excursion for the Tenth International Symposium on the Ordovician System, the Third International Symposium on the Silurian System, IGCP 503 annual meeting, Nanjing, June 2007 (Science Press, 2007)