New Mammals from Early Cretaceous and Their Implications for Deep Mammalian Phylogeny

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A grant has been awarded to Dr. Zhe-Xi Luo of Carnegie Museum of Natural History in Pittsburgh to study some exquisitely preserved fossil mammals from China, made available through an international collaboration with the Chinese scientists. These fossil mammals from the Early Cretaceous Feathered Dinosaur sites are about 125 million years old. They represent the earliest known relatives to modern marsupials (such as opossums and kangaroos) and placentals (such as whales, bats, dogs, and humans). Marsupials and placentals collectively make up 99.9% of all living mammals; and they have dominated the world in the Cenozoic (65 million years to the present). Dr. Luo plans to conduct an extensive evolutionary study of the skull and skeleton of these fossil mammals in order to establish the ancestral anatomical conditions from which modern marsupials and placentals are derived. He will also attempt a reconstruction of the family tree for major groups of mammals through the phylogenetic studies of these fossils. The family tree and the pattern of anatomical evolution to be established by Dr. Luo's planned studies will provide insight into the earliest history of all mammals.Humans are primates; primates are placentals; placentals are nested with a vast evolutionary bush of many extinct mammals that existed in the Mesozoic. Because a better understanding of early mammalian history can give meaning to our own existence, research findings in the early mammalian history can generate strong public interest, and will be useful for public science education. This research will be helpful for Dr. Luo to popularize science as a museum curator and to educate the public about evolution. The research findings will be disseminated by popular lectures and popular scientific publications. Some newsworthy discoveries made through this NSF-supported project can also be conveyed to a global audience through news media. Research on Mesozoic mammals can also be incorporated into the Carnegie Museum's new dinosaur exhibits scheduled for the next several years. This NSF project will also enable Dr. Luo to train graduate and undergraduate students in mammalian evolutionary biology, and to incorporate the latest research findings in his teaching at the University of Pittsburgh.