It’s well established: tree sloths are weird. So we can assume that extinct ground sloths were weird too. Studying sloths is tough because it’s hard/impossible to observe their behaviors, yet knowing their (paleo)ecology is important for conservation and interpreting paleoecosystems. Our project will use stable isotopes as a proxy for diet/habitat thus eschewing direct observation. This serves two goals: a better grasp of sloth ecology and a metric for applying these techniques to fossil sloths.