Developmental stages of Nucellangium ovules from middle Pennsylvanian Iowa [USA] coal balls clarify the morphology and vascularization of the nucellus and structure of the gametophyte. Two archegonia, one on either side of a prominent gametophytic beak, are deeply embedded in the apical end of the gametophytic tissue. The cellular remains of an undifferentiated embryo are present in 1 archegonium. Nucellangium is considered to be a cordaite ovule, based upon similarities between epidermal features of the ovule and Cordaianthus inflorescences. This conclusion is supported by the presence of a columnar epidermis on the ovules of C. zeilleri in the original slide collection of Renault.