The Sporormiella proxy and end-Pleistocene megafaunal extinction: A perspective

Abstract

Counts of dispersed spores of the pyrenomycete dung-fungus Sporormiella have recently gained prominence as a technique to examine the end-Pleistocene mass extinction. Early investigations were able to identify Sporormiella occurrence on the dung of extinct species, including squirrel and mammoth. These early studies also noted an important trend in Sporormiella abundance over time in North America, such that spore abundances were high during the late Pleistocene, low for most of the Holocene, and again prominent with the introduction of large grazing animals by early explorers. In more recent studies, changes in the abundance of spores of this fungus in sediments have been used as a proxy to define megafaunal population presence, decline, and extinction during the late Pleistocene, and a number of sites in the northeastern USA show a similar pattern of Sporormiella abundance over time. It is our opinion that some critical taxonomic and taphonomic investigations have not been completed for Sporormiella, and because of this, there are complications in interpreting the Sporormiella spore abundance data. We constructively evaluate this analytical technique and propose supporting studies that could enhance its potential as an indicator of megaherbivore extinction and its use as a proxy for the end-Pleistocene extinction.