There is now broad agreement among students of primate evolution that the last common ancestor of the living monkeys, apes, and humans (Anthropoidea) lived in Africa during the later part of the Eocene epoch, between about 45 and 34 million years ago. The primary fossil evidence documenting this critical phase in primate evolutionary history comes from sedimentary deposits exposed in the Fayum Depression, northern Egypt, which are 37 to 28 million years in age. Past work has revealed evidence for a diverse radiation of anthropoid primates that lived in this area 29 to 34 million years ago; the recent discovery of fossil anthropoids and other primates at a much older, 37 million-year-old, site in the area has now provided paleontologists with an unprecedented 8-million-year-long record of primate and non-primate mammalian evolution in this part of northern Africa. Over the course of three field seasons (in 2008, 2009, 2010) paleontological work in the Fayum area will help to reveal important new insights into the early evolutionary history of Anthropoidea, including the impact of one of the most dramatic changes to Earth climate during the Age of Mammals -- the rapid onset of Antarctic glaciation, and associated global cooling phase, which began about 34 million years ago at the Eocene-Oligocene boundary. A skilled team of vertebrate paleontologists, geologists, paleobotanists, and geochemists has been assembled to collect and analyze vertebrate fossils, plant fossils, and rock samples throughout this succession as a means for studying environmental change and primate and non-primate evolution and adaptation before, during, and after the climatic events at the Eocene-Oligocene boundary. Stable isotope data will be extracted from fossil specimens in order to date localities and reconstruct paleoenvironments. As such, our team will not only collect new vertebrate fossil material as in years past, but importantly also aims to place fossil sites into a well-dated framework so that patterns of biotic evolution and extinction can be evaluated within the context of both local and global environmental change.
Recovery and analysis of the fossil evidence that documents our shared evolutionary history with anthropoids and other primates is of great interest to the scientific community and the general public. Despite many years of paleontological research, a number of key questions remain unanswered; for instance, the roles that geography, plate tectonics, climate change, extinction, and competition have played in shaping our anthropoid ancestors' ancient evolutionary history continue to be actively debated. This research will provide paleontological field training for a number of young Ph.D. students, including members of groups that are underrepresented in physical anthropology and particularly paleoanthropology. This research will also allow American and Egyptian researchers to work together as part of an international collaboration that will provide new opportunities and resources for students and educators in both the U.S.A. and Egypt.
The ancient rock layers that are exposed along the northern rim of Egypt’s Fayum Depression have yielded hundreds of fossils that document an early phase in the evolution of Anthropoidea -- the primate group that includes monkeys, apes, and humans. This award funded three expeditions to the Fayum area (in 2008, 2009, and 2010) that allowed professional paleontologists and doctoral students from the U.S. and Egypt to recover additional fossil evidence from sites that range in age from ~37 to ~29 million years. Ongoing paleontological work in the Fayum area is of fundamental importance for our understanding of early primate evolution because ~80% of the primate species that are known from this extensive 8-million-year-long interval in Africa and Arabia have been found only at Fayum sites; several of these species are known from complete or partial skulls and numerous other skeletal parts, all of which provide unique insights into their lifestyles and evolutionary adaptations. Furthermore, these sites occur before, during, and after the major global cooling event that marks the boundary between the Eocene and Oligocene epochs, and provide the only detailed African record of land mammals’ evolutionary response to this climate shift. Our research team has announced several important discoveries since the beginning of this award, notably descriptions of the previously unknown Eocene primates Afradapis and Nosmips, both of which were made widely known to the public through National Science Foundation press releases. Major advances have also been made in the study of other vertebrate lineages that occur at Fayum fossil sites (for instance rodents, hyraxes, insectivores, bats, lizards, turtles, and both bony and cartilaginous fish). Much of this research is interdisciplinary; for instance, our research team has also undertaken high-resolution sampling of sedimentary rocks and vertebrate fossils, and these samples are currently being analyzed by geochemists for stable isotopes that will provide new information about the ancient environments in which our ancient primate relatives lived, and how those environments changed over time. The fossils that have been recovered on these expeditions have significantly augmented the collections of the Egyptian Geological Museum and the Duke Lemur Center Division of Fossil Primates, and will be available for countless future generations of vertebrate paleontologists, geologists, and geochemists. Both institutions are making fossil material available to interested researchers, and members of our research team are regularly employing computed tomographic ("CT") scanning to create three-dimensional digital models of fossils that can be quickly and easily distributed to researchers and students over the internet (and viewed with freely-available software). This award allowed 11 doctoral students to be trained in the field in Egypt between 2008 and 2010. Five post-doctoral scientists, 13 doctoral students, one undergraduate student, and three high school students were directly involved in the analysis and/or description of fossils from the Fayum area. Several of these participants are members of groups that are underrepresented in biological anthropology, and particularly the subfield of paleoanthropology. Since the start of the award, members of our research team have published 23 peer-reviewed papers in scientific journals (an additional four are in press as of May 2013) and 10 peer-reviewed papers in edited volumes, and have given 14 presentations at professional conferences and 13 invited lectures at various universities and museums in seven different countries. Two of the PI’s graduate students completed doctoral dissertations on Fayum fossil material. The important discoveries that have recently been made in the Fayum region are providing biological anthropologists with the data that they need to put together an increasingly detailed picture of our ancient anthropoid ancestors' lifestyles, habitats, and the evolutionary meaning of their anatomical adaptations. These new and increasingly complete discoveries will be made widely known to the general public through incorporation of this information into textbooks, websites, popular science articles, and other sources. This information is critically important for placing humans and their living primate relatives into the broader picture of Earth history that is emerging from ongoing research in the related fields of paleontology, geology, geochemistry, geochronology, and climate science.
