Nodosisporites choshiensis Legrand, Pons, Nishida & Yamada

Legrand, Julien, Pons, Denise, Nishida, Harufumi & Yamada, Toshihiro, 2011, Barremian palynofloras from the Ashikajima and Kimigahama formations (Choshi Group, Outer Zone of south-west Japan), Geodiversitas 33 (1), pp. 87-135 : 105-106

Nodosisporites choshiensis Legrand, Pons, Nishida & Yamada n. sp.

( Fig. 10 G-K)

Nodosisporites sp., Legrand, Palynologie des dépôts Jurassique supérieur et Crétacé inférieur du Japon, et provinces paléofloristiques du sud-est asiatique: 166, 167, pl. XIII, figs 3, 5, 6 (2009).

TYPE MATERIAL. — Site I, horizon 1, slides SEM-a, SEM-b; holotype (SEM-a; Fig. 10J ); paratype (SEM-b; Fig. 10K ). Collection de Paléobotanique-UPMC, Paris, France.

ETYMOLOGY. — The species name is after the Choshi Group, from which it was reported.

OCCURRENCE. — Ashikajima and Kimigahama Fm.

TYPE LOCALITY. — Kimigahama bay, Choshi Peninsula, Chiba Prefecture, Japan.

STRATIGRAPHIC HORIZON. — Kimigahama Fm (late Barremian).

DIAGNOSIS

Tetrahedral trilete microspore. Amb rounded triangular. Proximal face slightly flattened, with a psilate contact area followed by 1 or 2 muri parallel to the equator. The laesurae are relatively narrow, slightly raised and undulating, and extend to the 3/4 of the spore radius. The exine is cicatricose. The distal face is strongly convex (35 to 40 µm in polar diameter). It shows 3 sets of 3-4 muri parallel to the equator, that join in the apex areas. One of these sets goes on to form a triangle centered on the distal pole ( Fig. 11 ). The muri are raised, 2 to 3 µm wide, and are ornamented by tubercules, verrucae or spines (5 to 7 µm long) regularly distributed. The ornamentation of this form corresponds to the type I-A defined by Krutzsch (1963). Equatorial diameter = 35-50 µm; polar diameter = 35-40 µm.

REMARKS

Appendicisporites spinosus Pocock, 1964 shows supramural bacula, verrucae or spines as observed in Nodosisporites , but differs from the later in that these elements are not evenly distributed. Cicatricose or canaliculate genera Cicatricosisporites and Plicatella also show some morphological similarities, but both lack supramural elements.

BOTANICAL AFFINITIES

Schizaeales , Anemiaceae ( Dettmann & Clifford 1992) .

Figures

FIG. 10.— Spores from the Barremian of south-west Japan:A-F, Nodosisporites makotoi n. sp.(A, D, proximal and distal faces,Ashikajima Fm, II2a-L58/2; B, E, proximal and distal faces, Ashikajima Fm, II2b-E56/3; C, F, proximal and distal faces, Ashikajima Fm, II2b-U33); G-K, Nodosisporites choshiensis n.sp.(G, H, lateral view,Ashikajima Fm,II2b-K22/2;I, lateral view,Ashikajima Fm,II2b-E40b;J, proximal face, Kimigahama Fm, SEM-I1a; K, distal face, Kimigahama Fm, SEM-I1b); L-N, Cingulatisporites sp. 1 (L, proximal face, Kimigahama Fm,I1b-R41;M, N, proximal and distal faces, Ashikajima Fm,II2c-J26/3);O, P, Cingulatisporites psilatus Groot & Penny,1960,proximal and distal faces, Kimigahama Fm, I1a-W67g; Q, Cingutriletes sp., proximal face, Ashikajima Fm, II2a-H67g. Scale bar: 10 μm.

FIG. 11. — Ornamentation of the schizaealean forms corresponding to new species or taxa placed in open nomenclature.