THE FIRST FINDING OF GASTEROMYCETES IN THE CRETACEOUS OF MONGOLIA

Abstract

The first Cretaceous find of Gasleromycetcs comes from the Maastrichtian dinosaur beds of the Nemegt Basin, southern Gobi. A small group of fruiting bodies was found on the ferruginous surface of light gray clays containing abundant plant debris. Cretaceous fungal remains resemble Geastrum Pers., but differ in the irregular splitting of the exoperidium (a half of the exoperidium remains entire), a relatively small gleba indicating an early opening of the exoperidium, and larger spores. On account of these distinctions, a new genus, Geastroidea Krassilov gen. nov. is established. Mycelial films around the fruiting bodies might contribute to soil building on levee deposits. This find indicates that saprophytic fungi played a certain role in Cretaceous dinosaur ecosystems.