Collaborative Research: Micro- and Macroscopic Eukaryotic Life and its Preservation within the Mesoproterozoic Lower Belt Supergroup

Collaborative Research: Micro- and Macroscopic Eukaryotic Life and its Preservation within the Mesoproterozoic Lower Belt Supergroup The origin of eukaryotes (the domain of life that includes nearly all macroscopic organisms, animals, and plants) remains one of the most challenging and data-limited problems in all of evolution. Understanding the modern biosphere relies upon answering fundamental questions about the earliest evolution of eukaryotes: When and how did Earth’s earliest eukaryotes emerge, evolve, and subsequently radiate? Studying the excellently preserved fossils in the 1.5-billion-year-old Appekunny and Greyson Formations of the lower Belt Supergroup in western Montana will develop a unique and vital record for understanding eukaryotic evolution. The rocks are predominantly located on public lands, which are heavily utilized both locally and internationally for recreation and as tourist destinations. Through the development of educational resources and training sessions with natural tourism guides, this project will work to increase the public’s scientific literacy about deep time, the evolution of life, and local geology and integrate non-traditional STEM educators into the process of public science engagement. A comprehensive paleontological study has never been conducted on the Appekunny and Greyson Formations, but the formations contain the world’s third oldest macroscopic fossils—Horodyskia moniliformis and Grypania spiralis. This work will combine lithostratigraphy, magnetostratigraphy, and detrital zircon and monazite geochronological analysis, in conjunction with a broad expansion of their paleobiological data, to understand the temporal, environmental and paleobiological correlations between these two units. This project will additionally test competing hypotheses regarding taphonomic versus paleoenvironmental-ecological controls on fossil assemblage composition and diversity, perform stratigraphic microfossil sampling and resampling known macrofossiliferous strata, and characterize problematic fossil-types. Connecting the paleobiology, sedimentology, and geochemistry of these key units will enable broader inferences regarding the environments, ecosystems, and diversification patterns of Earth’s earliest eukaryotes. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.