Dicotylophyllum leptovenum Wang and Dilcher, 2009

Figure 26

Description. Leaf base asymmetrical. Apex missing. Base acute, decurrent. Margin entire. Petiole short, stout, 1 cm long and 1.5 mm wide. Primary venation pinnate; primary vein massive, multi-stranded, course straight, observed primary vein about 1.2 mm wide. Secondary venation brochidodromous; secondary veins thin relative to primary vein, 6 pairs observed in a 6 cm long lamina; secondary veins originating from primary vein at wide acute angle (ca. 70º), joining superadjacent secondary veins at a distance of about one fifth of half lamina to enclose an intercostal region; secondary veins uniformly curved, but becoming sinuous when they intersect with intersecondary veins. Intersecondary veins always present, two or three per intercostal region, simple. Tertiary veins course irregular, intersecting with intersecondary veins or randomly reticulate, anastomosing to form meshes irregular in shape and size. Quaternary veins irregular in course, exmedially ramified or forming incompletely closed meshes irregular in shape and size. Veinlets simple, curved. Vein pattern in excostal region not observed.

Number of specimens examined. 1.

Specimens illustrated. UF 15706-24734 (Figure 26).

Remarks. The specimen from Hoisington III locality has well-preserved high order veins compared with the specimen from the Courtland I locality, Minnesota.