Based on the distribution of the dendroids in Shansonggang, Xiaoyangqiao and other 5 localities from Santonghe and Hunjiang valleys, S. Jilin, four Cambrian - Ordovician graptolite zones or beds and two subzones are recognized in ascending order as follows: (1) Callograptus Bed (late Cambrian); (2) Dictyonema flabelliforme - Staurograptus dichotomus Zone (O1): (a) Dictyonema proparabola Subzone, (b) Dictyonema flabelliforme parabola Subzone, (3) Anisograptus richardsoni Zone (O1); and (4) Bryograptus cyclopterus Zone (O1). Among them Bed 1 and Zone 4 are proposed in the present study. A correlation of the graptolite zones and diagnostic descriptions of some species are given in the paper.
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