Figuring out moa diet is only the tip of the dungheap when it comes to ancient poop studies. Prehistoric dung has a wealth of uses for science, from tracking the demise of the mammoth to deciphering the peopling of the Americas. The spores of Sporormiella, a type of mold that loves nothing better than a nice pat of dung to grow over, have been used as a proxy to track the abundance of megafauna across the millennia. Carbon dating DNA-fingerprinted coprolites from the Paisley Caves in Oregon helped prove the presence of pre-Clovis humans (and, as a bonus, testing feces for DNA doesn’t raise the same ethical quandaries as testing ancient skeletal remains).
The climate history of the American Southwest was established in large part thanks to a deposit of sloth dung discovered in Arizona in the 1950s. The dung was left by the Shasta ground sloth, a small species as ground sloths go, more bearlike than the more famous Megatherium, which grew to the size of an elephant. For around 30,000 years, these sloths used Rampart Cave, a hollow in the side of the Grand Canyon, as their latrine. Pollen in the accumulated droppings recorded the shifts in vegetation that accompanied the arrival and departure of past glacial maxima. Crucially, they proved that the shift in vegetation and temperature that came with the end of the last Ice Age wasn’t particularly new or extreme. It was something that had happened multiple times in previous millennia.