This exploratory project searches for fossils on Livingston Island in the South Shetland Islands off of the Antarctic peninsula. Strata there date from 125 to 99 million years in age, a critical time in the development of various flora and fauna. With so many unknowns in the biotic history of the Antarctic, any finds of vertebrate fossils on this little explored island will be of great significance. One key question is marsupial evolution. It is assumed that marsupials of South America and Australia transited through Antarctica, but a supporting fossil record has yet to be discovered. Related investigations on Mesozoic climate will be performed through stable isotope analysis of clay and rock samples. The broader impacts of the project include graduate student education and public outreach through a museum exhibit.
Among the great unknowns in the history of life is the role that Antarctica played in vertebrate evolution during the key interval encompassed by the Late Cretaceous and early Paleogene (~100-40 million years ago). Was this now-frozen landmass marginal to important biotic events occurring elsewhere, or did it play a critical role in, for example, the early evolution and diversification of modern bird and mammal lineages? Tantalizing paleobotanical evidence indicates that Antarctica was home to a diverse flora during the Late Cretaceous and Paleogene, yet the vertebrates that must have existed on the continent under any plausible scenario remain virtually unknown. Our goal was to intensively search for and collect Late Cretaceous-Paleogene Antarctic vertebrate fossils at localities that have never been properly surveyed as well as in areas of proven potential. Through partnerships with specialists in a variety of related disciplines (e.g., paleobotany, invertebrate paleontology, sedimentology, taphonomy, geochronology), we are seeking to place fossil discoveries within accurate and detailed temporal, paleoenvironmental, and paleoecological contexts. Focusing on the James Ross Island Group on the northeastern margin of the Antarctic Peninsula; we recovered a wide variety of vertebrate fossils relating to chondrichthyan and osteichthyan fishes (sharks and bony fishes), marine reptiles (plesiosaurs and mosasaurs), ornithischian and non-avian theropod dinosaurs, ornithurine (modern) birds, and therian mammals (marsupials and placentals). As a result we have been able to make contributions to a number of scientific questions: (1) Did modern bird lineages originate during the Cretaceous, perhaps in Gondwana? 2) Did the "Scotia Portal" joining southernmost South America to the Antarctic Peninsula permit the dispersal of continental vertebrates prior to its disappearance in the mid-Eocene (40 million years ago)? 3) Were Late Cretaceous non-avian dinosaurs from Antarctica closely related to species from other Gondwanan landmasses? 4) Was the collapse of Antarctic fish diversity triggered by the same catastrophic extinction at the end of the Cretaceous that caused the demise of the non-avian dinosaurs? Project members have communicated discoveries to public audiences through a variety of channels, including the Dinosaurs in Their Time exhibition at Carnegie Museum of Natural History and The Race to the End of the Earth, a major traveling exhibition created by the American Museum of Natural History which received partial funding from the NSF. A total of six graduate students and field assistants from a variety of universities received field training in the extreme Antarctic environment, and helped with the analysis of fossils. Scientific results have and will continue to appear in specialist publications and presentations at professional conferences, thus contributing to research and educational infrastructure.
