ABSTRACT
Mycophagy of fungal sporocarps by a great diversity of animals is documented for all continents except Antarctica and entails a range of behaviors and nutritional modes (Fogel and Trappe, 1978; Maser et al., 1978; Emmons, 1982; Perez Calvo et al., 1990; Janos and Sahley, 1995; Claridge et al., 1996; Luoma et al., 2003). With few exceptions, it involves mycorrhizal associations originated with the earliest vascular plants more than 400 million years ago. The fossils of these mycorrhizae show morphologies consistent with presentday arbuscular mycorrhizae and were probably formed with glomalean fungi that formed individual spores or spore clusters in the soil. The spores would have been dispersed by soil movement and perhaps mycophagy by primitive invertebrates. Host genera that today form ectomycorrhizae first appeared about 150 to 200 million years ago, as did mammals. The fossil record so far is silent on the earliest appearance of ectomycorrhizae and ectomycorrhizal fungi, but it was likely close to the same time. Distributions of related ectomycorrhizal host genera and associated fungal genera in both the northern and southern hemispheres suggest common ancestries in the supercontinent Pangaea before it began to
separate into the southern Gondwana and northern Laurasia some 180 million years ago. Hypogeous genera do not likely disperse across even limited ocean barriers, yet the genus
Elaphomyces
includes closely related species with identical, complex peridial structures in both the northern and southern hemispheres, suggesting origins in Pangaea prior to its breakup (Trappe et al., 2001).
