Cyclosorus iddingsii (Knowlt.) Corr.-Narvaez et Yañez in MacGinitie

Emended Diagnosis:
1-pinnate pinnatifid frond fragments. The fossils had a stout axial vein, with alternating pinnae, diverging at ca. 45°-65° from it, and decreasing in size and complexity toward apex, ending in a conform apex, pinnatifid. Penultimate segments discrete, pinnatifid, slightly asymmetrical, and oblong, tapering towards the tip, ca. 10-18 cm long and ca. 1.5-2 cm width, with ca. 12-20 or more pinnatifid ultimate segments, a catadromous basal segment and a short, or absent, “stipeolule.”. Ultimate segments symmetrical, oblong-weakly falcate, with entire margins, and blunt, short straight, or rounded apexes,ca. 5-15 mm long and ca. 3-6 mm width, decreasing in size and complexity distally. Ultimate segments axial vein mostly straight,diverging at 55-75°, occasionally curving near the apex; 6-10 mostly free lateral veins diverge, curving slightly and very rarely forking, approaching the margin; the basal-most pair of lateral veins converge with the corresponding veins of the adjacent segment, forming distinctive triangular areoles and a straight excurrent vein that terminates at the sinus. Some fossils display very thin ‘elongated’ expansion of the lateral veins. Sori round, 0.5-0.9 mm diam., on the lateral veins, midway between the axial vein and the margin, protected by round to strongly recurved kidney-bean (reniform) indusia; the sori have ca. 20-40 sporangia.