Notes on Cambrian trilobite biogeography of China

Although there is no reliable information hi-therto reported from the Northern Xinjiang and Southern Tibet terranes,Cambrian trilobites are widely distributed in China. Trilobite evidence indicates that all the plates and some of the other terranes (including the Middle and Late Cambrian Middle Tianshan-Beishan Terrane) in China exhi-bit a close biogeographic link and may have formed part of eastern Peri-Gondwana during the Cambrian,with the exception of the Hinggan Region and the Early Cambrian Middle Tianshan-Beishan Terrane where trilobite faunas instead show a strong affinity with those of Siberia and Laurentia. Well-defined biogeographic patterns are depicted mainly by the shallow-water components of the Cambrian trilobites,especially in the South China,Tarim and North China plates. Our synthetic analysis suggests that although these Chinese eastern Peri-Gondwanan plates and terranes may be assignable to a single biogeographic province during the Middle and Late Cambrian,they display significant differences and may,therefore,be separated into two subprovinces during the Early Cambrian in view of data currently available:one consisting of South China,Tarim and Annamia,and the other represented by the North China Plate only.