Chinese Neogene Rhinocerotidae has quite a complete record and its temporalrange is the Early Miocene to Late Pliocene. The samples include 25 species in 4 tribes of 2subfamilies. They are used as a foundation for the...Chinese Neogene Rhinocerotidae has quite a complete record and its temporalrange is the Early Miocene to Late Pliocene. The samples include 25 species in 4 tribes of 2subfamilies. They are used as a foundation for the study of the evolution of the family and itsrelation to climatic changes. Taxonomic diversity, new records and extinctions are estimated foreach Chinese Neogene mammal faunal unit (NMU). The diversity of Chinese Rhinocerotidae variesnoticeably throughout the Neogene and is recognized within five stages: the Middle Miocene and LateMiocene are stages of high diversity and the Early Miocene, early Late Miocene and Pliocene arestages of low diversity. Rhinocerotid diversity and morphology are closely related to environmentalfactors and particularly sensitive to changes in ambient temperature and humidity. Theinterpretation of climatic variation reflected in the evolution of Rhinocerotidae correspondsprecisely with the conclusions drawn from other workers and provides new evidence for research onthe Neogene terrestrial ecosystem in China.展开更多
The consensus view among geologists is that the Lanzhou Basin sequence of sedimentscontains the Oligocene/Miocene boundary, but where this occurs is unknown. Indeed, this is thecrux of the issues concerning mid-Tertia...The consensus view among geologists is that the Lanzhou Basin sequence of sedimentscontains the Oligocene/Miocene boundary, but where this occurs is unknown. Indeed, this is thecrux of the issues concerning mid-Tertiary paleontology in Asia: what fauna corresponds with thistime? What turnover events or distinctive taxa signal the beginning of the Miocene epoch? Onceknown, this will be of broad usefulness because vertebrate-bearing deposits are widespread in Asiaand can be used to date basin sediments. Lanzhou and other basins permit a means of correlating tothe time scale by using fauna and paleomagnetic data locally, and ultimately radiometric data fromdistant localities, to develop a precise biochronology. Herein, we summarize faunal constraints,primarily those of small mammal taxa, on correlation of the Lanzhou magnetozone sequence to themagnetic time scale. We conclude that the lower part of the Xianshuihe Formation contains theOligocene/Miocene boundary, and that the top of the formation, both in the south and north partsof the basin, is middle Miocene in age. Rodents from lower white sand units of the XianshuiheFormation, correlate to the Xiejia assemblage of the Xining Basin, Qinghai Province, and are early,but not earliest, Miocene age. The implication for rodent faunas of the epoch boundary is that theyretained a mainly "Oligocene" composition, and that other presumed late Oligocene assemblagesmay be, in fact, early Miocene in age. The Lanzhou appearance of Proboscidea is 19-18 Ma, asexpected.展开更多
基金the Knowledge Innovation Project of the Chinese Academy of Sciences(KZCX2-103) the Major State Basic Research Project of China(G2000077700).
文摘Chinese Neogene Rhinocerotidae has quite a complete record and its temporalrange is the Early Miocene to Late Pliocene. The samples include 25 species in 4 tribes of 2subfamilies. They are used as a foundation for the study of the evolution of the family and itsrelation to climatic changes. Taxonomic diversity, new records and extinctions are estimated foreach Chinese Neogene mammal faunal unit (NMU). The diversity of Chinese Rhinocerotidae variesnoticeably throughout the Neogene and is recognized within five stages: the Middle Miocene and LateMiocene are stages of high diversity and the Early Miocene, early Late Miocene and Pliocene arestages of low diversity. Rhinocerotid diversity and morphology are closely related to environmentalfactors and particularly sensitive to changes in ambient temperature and humidity. Theinterpretation of climatic variation reflected in the evolution of Rhinocerotidae correspondsprecisely with the conclusions drawn from other workers and provides new evidence for research onthe Neogene terrestrial ecosystem in China.
文摘The consensus view among geologists is that the Lanzhou Basin sequence of sedimentscontains the Oligocene/Miocene boundary, but where this occurs is unknown. Indeed, this is thecrux of the issues concerning mid-Tertiary paleontology in Asia: what fauna corresponds with thistime? What turnover events or distinctive taxa signal the beginning of the Miocene epoch? Onceknown, this will be of broad usefulness because vertebrate-bearing deposits are widespread in Asiaand can be used to date basin sediments. Lanzhou and other basins permit a means of correlating tothe time scale by using fauna and paleomagnetic data locally, and ultimately radiometric data fromdistant localities, to develop a precise biochronology. Herein, we summarize faunal constraints,primarily those of small mammal taxa, on correlation of the Lanzhou magnetozone sequence to themagnetic time scale. We conclude that the lower part of the Xianshuihe Formation contains theOligocene/Miocene boundary, and that the top of the formation, both in the south and north partsof the basin, is middle Miocene in age. Rodents from lower white sand units of the XianshuiheFormation, correlate to the Xiejia assemblage of the Xining Basin, Qinghai Province, and are early,but not earliest, Miocene age. The implication for rodent faunas of the epoch boundary is that theyretained a mainly "Oligocene" composition, and that other presumed late Oligocene assemblagesmay be, in fact, early Miocene in age. The Lanzhou appearance of Proboscidea is 19-18 Ma, asexpected.
