Abstract:   Polecat Bench and McCullough Peaks in the northern Bighorn Basin of Wyoming have yielded major discoveries leading to understanding both mammalian biostratigraphy of the North American Paleocene, and the pattern and cause of continental faunal turnover at the Paleocene-Eocene thermal maximum. In 1910, Princeton and American Museum paleontologists showed that mammals of the Paleocene were distinctly different from those of the Eocene. This soon led to acceptance of the Paleocene as an epoch different from the Eocene. Eighty years later, Michigan and Carnegie Institution paleontologists showed that the continental Paleocene-Eocene boundary was marked by abrupt faunal turnover and dwarfing associated with a major carbon isotope excursion. This led to recognition of the Paleocene-Eocene thermal maximum or ‘PETM’ as a greenhouse warming event that was truly global. A young scholar involved in paleontology in 1950, Minchen Chow, was introduced to field work on Paleocene mammals in Wyoming. There he developed the experience and expertise that led to parallel exploration of the Paleocene in China. The challenge now is to understand how the parallel Paleocene histories of the North American and Asian continents fit together. 

摘要： 怀俄明州大角盆地北部的Polecat台地和麦卡洛峰的重要发现对了解北美古新世哺乳动物生物地层以及古新世？始新世极热事件中陆生动物群更替模式和原因具有重要意义。1910年，普林斯顿大学和美国自然历史博物馆的古生物学者指出，古新世的哺乳动物与始新世的明显不同，这使得古新世是一个不同于始新世的时期的观点很快被接受。80年之后，密歇根大学和卡耐基研究院的古生物学者指出，陆相古新统？始新统界线可以用动物群的快速更替和小型化作为标志，并伴随着一次重要的碳同位素漂移，这使得古新世？始新世极热事件(PETM)作为真正的全球性温室升温事件得到了公认。1950年，投身古生物事业的年轻学者周明镇被介绍到怀俄明参加古新世哺乳动物野外工作。在那里，他积累了专业知识和经验，并促成了对中国古新统进行的类似考察。现在的挑战是如何将北美和亚洲大陆相似的古新世历史拼合在一起。