Recent research indicates that members of the extinct conifer family Cheirolepidiaceae were an important component of low latitude Mesozoic floras, and possessed many derived features including an angiosperm-like sporophytic incompatibility system based on the tectate-columellate pollen wall morphology and partially enclosed ovules. However, a more complete understanding of this group has been hampered by the rarity of reconstructions including ovulate cones. Here, we describe the first cheirolepidiaceous conifer from North America with attached ovulate cones. The specimens come from the Lower Jurassic Portland Formation of Connecticut and include branching systems of up to three orders with attached ovulate cones and associated pollen cones. Leaves are of the Geinitzia morphotype and are the longest known in the family. Ovulate cones are terminal on short side branches and bear helically arranged bracts with acute apices. The cone scales are completely flattened, and each has nine elongate lobes along the distal margin. Ovules were born in a circular depression on the adaxial scale surface. The ovoid pollen cones are the largest known in the family and contain Classopollis pollen. This fossil is most similar to Hirmeriella from the Lower Jurassic of Europe, and Tomaxellia from the Lower Cretaceous of South America. The large number of cone scale lobes suggests that the North American form may be primitive within the family. A preliminary phylogenetic analysis incorporating data from this fossil supports recent suggestions that the Cheirolepidiaceae and Majonicaceae are closely related.

Key words: Cheirolepidiaceae, Conifers, Jurassic