自始新世以后中国南、北方动物群分异越来越明显，可能与青藏高原的逐渐隆起密切相关。中国新生代哺乳动物与欧洲和北美大陆都有过交往，早期与北美大陆交流较多，晚期则与欧洲关系更为密切。 Since the Eocene, the differentiation of fauna in the south and the north of China has become more and more obvious, which may be closely related to the gradual uplift of the Qinghai-Tibet Plateau. The new generation of mammals in China and Europe and North America have had contacts, early exchanges with the North American continent more late with the European relations more closely.