The morphology and phylogenetic significance of Vardekloeftia harris (Bennettitales)

Abstract

The genus Vardekloeftia Harris, a bennettitalean reproductive structure from the Upper Triassic of East Greenland, is reinvestigated from the original material and from more recent collections. The two previously described species are combined as V. sulcata Harris and new generic and specific diagnoses, as well as more detailed descriptions, are provided. In the ovule of Vardekloeftia the nucellus is surrounded by two distinct layers (integument and cupule). Comparisons indicate that this kind of ovule structure also occurs in other Bennettitales and may be general within the group. The probable leaves of the Vardekloeftia plant are Pterophyllum kochii Harris. The pollen organs are unknown, but Bennettistemon amblum Harris and Bennettistemon ovatum Harris are associated with Vardekloeftia and clumps of pollen very similar to that of these species occur in the micropyles of Vardekloeftia seeds. Comparison of Vardekloeftia with other Bennettitales suggests that pollination and dispersal may have been relatively unspecialized in this early member of the group.