Microreticulatisporites sp. 1

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 : 104

Microreticulatisporites sp. 1 ( Fig. 8M, P )

OCCURRENCE. — Kimigahama Fm (one specimen).

DESCRIPTION Microspore. Amb circular. The laesurae are not seen. Exine microreticulated and finely scabrate. The mesh is polygonal, of various shapes and sizes (lumina 0.2 to 1.5 µm in diameter). The exine is 2 µm thick. Equatorial diameter = 40-45 µm.

BOTANICAL AFFINITIES

The ornamentation of this species shows similarities with that of some Polypodiales (Dennstaedtiaceae) figured by Tryon & Lugardon (1991). Moreover, the genus may have sphenophyte affinities, e.g. with the Noeggerathiales ( Knox 1950; Singh 1964).

Figures

FIG. 8. — Spores from the Barremian of south-west Japan: A-C, Retitriletes sp. (A, proximal face, Kimigahama Fm, SEM-I1a; B, lateral view, Kimigahama Fm, SEM-I1a; C, distal face, Kimigahama Fm, SEM-I1c); D, E, H-J, Foveosporites ryosekiensis n. sp. (D, E, proximal and distal faces,Ashikajima Fm,II2a-U63;H, proximal face,Ashikajima Fm,SEM-II2a;I, proximal face,Ashikajima Fm,SEM-II2b;J, lateral view, Kimigahama Fm, SEM-I1c); F, G, Retitriletes austroclavatidites (Cookson, 1953) Döring, Krutzsch, Mai & Schulz in Krutzsch, 1963, proximal and distal faces, Ashikajima Fm,II2b-O45/3;K, L, S, T, Cicatricosisporites sinuosus Hunt,1985 (K, L, proximal and distal faces, Ashikajima Fm,II2d-D55/4;S, T, proximal and distal faces,Ashikajima Fm,II2b-N33/1); M, P, Microreticulatisporites sp.1, distal face with detail, Kimigahama Fm, SEM-I1a; N, O, Microreticulatisporites sp. 2, proximal and distal faces, Ashikajima Fm, II2b-T23d; Q, R, Cicatricosisporites hughesi Dettmann, 1963, proximal and distal faces, Ashikajima Fm, II2h-E52/1. Scale bars: 10 μm.