Megaglomerospora lealiae nov. gen., nov. sp. from the upper Carboniferous of Portugal: the largest glomeromycotan fungal spores

Abstract

A new genus and species of fossil fungus, Megaglomerospora lealiae, is described from the Buçaco Carboniferous Basin (upper Stephanian C, Upper Pennsylvanian, upper Carboniferous), in central western Portugal. The new fossil fungus consists of a dense cluster of silicified large spores. These new fungal spores are oblong, subelliptical to subspherical-shaped, with a glabrous surface characterized by having a lipid-filled lumen, and display a strong septate-like hypha attached. The presence of lobe-shaped germination shields suggests close affinities to Diversisporales (Glomeromycota). Megaglomerospora lealiae nov. gen., nov. sp. is remarkably distinctive because it is by far the largest fossil fungal spore (∼1.6 mm long) documented for the phylum Glomeromycota. This is the first report of an endomycorrhizal‐like fungus from the Carboniferous of Iberia.