Eostangeria Barthel (extinct cycadales) from the Paleogene of western North America and Europe

Fernlike leaflets from the Paleocene of Wyoming and Eocene of Oregon are re cognized as cycad foliage based on diagnostic epidermal structure. The foss ils conform to Eostangeria Barthel, an extinct genus based on Eocene foliag e from German): and are described as a new species, Eostangeria pseudopteri s I(Kvacek et Manchester. Eostangeria resembles the extant South African cy cad Stangeria T. Moore (Stangeriaceae) in gross morphology (featherlike lea flets with dentate margin), but the fossil more closely resembles Zamiaceae in epidermal structure. Convergence in pinnule form and venation makes it difficult to distinguish Eostangeria from Allantodiopsis Knowlton et Maxon, a fern common in the Paleogene of North America, whose epidermal anatomy r emains unknown. However, the cycad can be distinguished in well-preserved s pecimens by the presence of interstitial fibers and secondary veins that oc casionally fuse at the margin. The occurrence of Eostangeria in the Tertiar y of both Europe and North America indicates that it may have spread across the North Atlantic region.