Sporormiella fungal spores, a palynological means of detecting herbivore density

During the historic period, spores of the dung fungus Sporormiella are abundant in lake and cave sediment where livestock are plentiful in the western United States. Sporormiella spores occasionally exceed 50% of the upland pollen sum in samples from corral ponds and bed-grounds, and routinely reach 4% in lake and marsh samples in pastoral areas. Sporormiella spores are comparatively rare in mid-Holocene sedimentary records, but they reach values of 2–4% in Pleistocene samples from lake sediments. Sporormiella spores are directly linked to extinct megaherbivores by their presence in mammoth dung from Bechan Cave, Utah. In several sites in the western United States, a precipitous decline of Sporormiella percentages after ca. 10,800 radiocarbon yr B.P. (12,900 years ago) marks a decline of herbivore density, probably associated with the North American megaherbivore extinction.