Sporormiella produces spores in the dung of large herbivores. These are then preserved in the layers of mud and can provide an index of the number of these animals, or megafauna, that roamed the environment at a particular time.
“Sediment cores are much like ice cores, except with lake mud,” explained Dr Gill. “The spores [and other materials] settle out into the lake mud and get buried over time.”
She and her team simply counted the pollen, charcoal and Sporormiella in these layers of mud, tracking the timescale of ancient environmental changes.
Their results showed a slow decline in megafauna that began about 15,000 years ago and appeared to last for about 1,000 years.