The Research On Cambrian Polymerid Trilobites From Shimenzhai Funing County And The Ecological Environment

Shimenzhai town is located at 28 kilometers to the north of Qinhuangdao City, in the eastern part of the Yanshan Mountains, to the south of which is the North China Plain and Bohai Bay, belonging to Funing County, Qinhuangdao City, Hebei Province.Three ecological types of Cambrian trilobites is analyzed in this paper, which are southeast type, North China type, and transitional type. The reason why demersal trilobites prospered heavily in one region is concluded through taking the ecological features and living environment of polymerid trilobites for example. The relationship between paleogeographic features and sedimentary biological structure interacting isdiscussed considering paleogeographic features. We came to the conclusion that distribution of different biocoenosis is controlled by environment, and the evolution and prosperity of different biocoenosis is related to their living environment closely besides their internal cause. Paleoclimate and paleogeographic environment restricted biological development, while the living style, habit and ecological features of biogroup reflected the geographical landscape of nature at that time.Author studied the Cambrian strata and biogroup of trilobites further with references to research results published by some scholars years ago, and we drew strata section figures and restored pictures of living trilobites. We deduce and prove that it was a normal coastal environment where there were plenty of sunlight, the ocean salinity was normal, oxygen was enough and marine life was prosperous by studying paleogeographic environment, the morphological construction of trilobites and the structural features of sedimentary rocks around.