Published online by Cambridge University Press: 20 May 2016
Palynoflorules containing sparse but regularly occurring chitinous-walled fungal, probably ascomycete, spores have been obtained from silty limestone nodules in the Jurassic Coon Hollow Formation in the Wallowa terrane in Hells Canyon, Idaho. The fungal spores are associated with moderately abundant embryophytic spores and pollen that suggest late Early Jurassic to early Middle Jurassic age, which agrees with dating provided by marine animals stratigraphically just above. The fungal spores constitute the most diverse such assemblage of robust-walled spores described from pre-Cretaceous rocks. Two new species of the fossil fungal spore form-genus Diporicellaesporites, D. idahoensis and D. serratulus, and one new species of form-genus Fractisporonites, F. pittsburgensis, are described.