Foveosporites ryosekiensis Legrand, Pons, Nishida & Yamada, 2011

Foveosporites ryosekiensis Legrand, Pons, Nishida & Yamada n. sp. ( Fig. 8D, E View FIG , H-J)

Foveosporites sp., Legrand, Palynologie des dépôts Jurassique supérieur et Crétacé inférieur du Japon, et provinces paléofloristiques du sud-est asiatique: 149, pl. V, fig. 16; pl. VI, figs 1, 2 (2009).

TYPE MATERIAL. — Site II, horizon 2, slide a; slides SEM-a, SEM-b; holotype ( II2 a-U63; Fig. 8D, E View FIG ) ; paratypes ( SEM-II2 a, SEM-II2 b; Fig. 8H, I View FIG ). Collection de Paléobotanique-UPMC, Paris, France .

ETYMOLOGY. — The species name is after the Ryosekitype Province of Japan, of which this species seems to be characteristic.

OCCURRENCE. — Ashikajima and Kimigahama Fm (common).

TYPE LOCALITY. — Hatoyama, SE Choshi Peninsula, Chiba Prefecture, Japan.

STRATIGRAPHIC HORIZON. — Ashikajima Fm (Barremian).

DIAGNOSIS

Trilete microspore. Amb triangular with straight to slightly convex sides. The laesurae are undulating, slightly raised ( 1-2.5 µm), and extend to the 3/4 of the spore radius. The contact area is psilate or can sometimes present one tubercule, and is delimited by a triangular thickening of the exine ( 3-4 µm wide), which overhangs and includes the trilete mark, and can extend to the apices. Beyond this thickening, the exine is psilate on the proximal face and forms a broad equatorial flange. The equator and the distal face are densely pitted to foveolate. On the distal face, the foveolae are more or less rounded, coarser near the equator ( 0.5 to 1.5 µm wide). The exine is 3 to 4 µm thick. Equatorial diameter = 35-45 µm; equatorial flange width = 5-7 µm.

REMARKS

Foveosporites labiosus Singh, 1971 has a thickening on its distal face similar to that observed in F.ryosekiensis , but its location is different. The equatorial flange reminds the Cyatheales (Lophosoriaceae) figured by Tryon & Tryon (1982).

BOTANICAL AFFINITIES

Lycopodiales , Lycopodiaceae .