Animal diversities and characteristics of environmental change revealed by skeletons unearthed at Zhongba Site of Chongqing City, China.

Nearly 200000 animal skeletons are unearthed in the Unit T0202 from Zhongba Site of Zhongxian County. According to the analysis of 129165 specimens, these skeletons may be classified into 5 kinds, namely, Mammalia, Osteichthys, Ayes, Amphibian and Reptilia, which belong to 13 orders, 28 families and 42 genera. In this paper, based on archeological dating and AMS14C data, through statistically analyzing the unearthed skeletons and studying the change of the smallest individual numbers, these research results detected the following: 1) In almost all the time of 2370-200 BC, in Zhongba region, some animals distributed widely, such as Muntiacus sp, Elaphodus cephalophus and Muntiacus sp. inhabiting in glade and grassland, Scrofa sp. and Canis famiiaris raised by the ancient people, rodentia rabbit and Rattus rattus, which suggested that a fairly good ecological environment of forest and grassland was preserved at that period and the predecessors began to raise domestic animals from 1750 to 1000 BC, which has lasted until today. 2) Rhinoceros only lived during 2000-1750 BC, 1000-700 BC and 700-500 BC, which indicates that the ecological environment of grassland and wetland might be better in these phases. 3) Macaca sp. and Ursus arctos appeared only after 1750-1000 BC, which may show that the forest condition is better for animals to live during 1750-200 BC. 4) The smallest individual numbers of Bublus sp., bos sp. and otters emerged during about 2370-1750 BC, which perhaps infers that water area during the early period was wider than that of the late period. 5) Since skeletons of rhinoceros are discovered in strata of Zhongba Site during 2000-1750 BC and 1000-500 BC, according to the climate and ecology environment which rhinoceros live in now, the average annual temperature and precipitation during 2000-1750 BC and 1000-500 BC are supposed to be probably higher than that of today. Although Zhu Kezhen considered that the first low temperature period in the past 5000 years of China was between 1100 BC and 850 BC, massive pollen of Morus, Ulmus, Fagus, Quercus, Castanea, etc. were found in Dajiuhu peat at that time, which should indicate that the climate was still moderate for living things to live at least in Dajiuhu basin and Zhongba Site. 6) Because skeletons of Gervus albirostris were unearthed during 310-200 BC at Zhongba Site, based on the climate and the ecological environment those animals live in now, the average annual temperature and the average annual precipitation in Zhongba area between 310 BC and 200 BC should be lower than those of today, which is confirmed by the TOC research of Zhongba Site strata. [ABSTRACT FROM AUTHOR]