Sporophyll organization in the Triassic isoetalen lycopsid Lepacyclotes from Germany

Annalepis zeilleri is one of the most frequently recorded Middle Triassic lycopsid fossils in central Europe and China. The taxon includes tongue-shaped sporophylls with a blunt to mucronate apex and an adaxial sporangium. However, little is known about the arrangement of the sporophylls and the morphology of the plant that produced them. Specimens from the Middle Triassic of Germany consist of wide axes in cross section surrounded by tightly clustered A. zeilleri sporophylls. This suggests that the sporophylls were produced in a strobilus or in intercalary fertile zones along an axis. Moreover, the fossils correspond in structure to certain other Triassic lycopsid remains that are described as Lepacyclotes circularis and L. bechstaedtii; they thus strengthen the concept that Annalepis and Lepacyclotes are congeneric. Since Lepacyclotes has priority over Annalepis, Lepacyclotes zeilleri is the correct name for the taxon.