ON THE TAXONOMIC STATUS OF SPECIES, GEOLOGICAL DISTRIBUTION AND EVOLUTIONARY HISTORY OF AILUROPODA

The paper attempts to elucidate the taxonomic status of species, geological distribution, and evolutionary history of Ailuropoda.1. The taxonomic status of speciesThe author shares the opinion that the giant pandas are to be classified under a separate family Ailuropodidae. Based on materials already discovered, only one genus, two species, including a subspecies may be recognized in this family:Ailuropoda microta PeiAiluropoda melanoleuca baconi (Woodward)Ailuropoda melanoleuca (David)Ailuropoda melanoleuca baconi includes the giant panda fossil (Ailuropoda fovea-lis Matthew et Granger), which is said to have spread extensively during the Middle and Late Pleistocene in various places south of Yangtze River in our country, and another fossil skull------Ailuropoda baconi (Woodward discovered in Mogok, Burma.2. Geological distribution and evolutionary historyStarting from the Late Tertiary, Ailuropoda microta, formed a separate branch from the ancestral stock. It prospered in the Early Pleistocene, but became extinct in Early Middle Pleistocene epoch. Up till now fossils have only been discovered in a cave in Liucheng, Kwangsi.By the Middle Pleistocene, when Ailuropoda microta developed into A. melano-leuca baconi, their body si2e experienced a prominent change. Most individuals of the small-sized type, being unable to adapt themselves to the new environmental conditions, gradually disappeared through natural selection. Only those individuals which had their body size enlarged were able to exist and to develop gradually, forming a new species, A. melanoleuca baconi, which spread extensively in our country southward to Burma.During the Late Pleistocene, with the appearance of man and the increase of human activities, A. m. baconi showed a distinct decrease both in the range of distribution and in the density of population. The tendency of declining is still in the continuing.Among the causes leading to the declining of the giant pandas, the development of man and the increase of human activities through space are external factors not to be neglected, but these external factors acted only through the internal cause of the giant pandas themselves.