AURITIFOLIA GEN. NOV., PROBABLE SEED PLANT FOLIAGE WITH COMIOID AFFINITIES FROM THE EARLY PERMIAN OF TEXAS, USA

Auritifolia waggoneri gen. et sp. nov. has compound leaves and is possibly a peltasperm, with venation similar to Comia Zalessky. The frond is once pinnate, >40 cm in length, with a short petiole, subopposite pinnae, increasing in size distally, terminating in two elongate pinnae. The petiole base is swollen. Fronds probably abscised upon senescence. Venation is three ordered, each higher order of progressively smaller diameter. Pinna midveins arise from the main rachis and give rise to secondary veins. Two types of tertiary veins are present. One type arises from the secondaries and forms fascicles; the other type is interfascicular and arises directly from pinna midveins. All tertiaries are of the same diameter. Tertiary veins dichotomize, anastomose, and may terminate in blind endings, so not all extend to the laminar margin. Laminae are amphistomatic. Monocyclic stoma are surrounded by five to six subsidiary cells. Epidermis and palisade parenchyma are uniseriate. Auritifolia is most similar to Comia in which the tertiaries lack anastomoses and blind endings and terminate at the laminar margin. The leaf architecture of Auritifolia differs significantly from that of Comia. (Russian and Chinese translations of this abstract are available in the online edition of International Journal of Plant Sciences.)