Some megaspores and other small fossils from the Wannagan Creek site (Paleocene) of North Dakota

Abstract The geology and inferred depositional environment of the Wannagan Creek site are discussed. The occurrence of Minerisporites mirabilis, Azolla stanleyi, and Dictyothylakos sp. are discussed within this context. A great deal of variation is noted in M. mirabilis, both in the dispersed population and in populations recovered from individual sporangia of Isoetites horridus, the parent plant. Vegetative remains of A. stanleyi are described, and anomalous megaspores and microspores without attached floats or massulae that were associated with the vegetative portion are discussed. Three forms of Dictyothylakos are described, and affinities with the Trichoptera (Insecta) are suggested. The habitats of these organisms are inferred using an interpretation of the geology of the Wannagan Creek site.