Retitriletes sp., 1961

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

Retitriletes sp.

( Fig. 8 A-C)

OCCURRENCE. — Kimigahama Fm.

DESCRIPTION

Trilete microspore. Amb rounded triangular. The laesurae are straight, slightly raised, and extend to the ⅔ of the spore radius. The contact area is psilate, followed by a reticulum with polygonal lumina of various shapes and sizes ( 3-8 µm in diameter; muri about 2 µm high) near the equator and on the distal face. The exine is about 2.5 µm thick. Equatorial diameter = 40-45 µm.

BOTANICAL AFFINITIES

Döring et al.in Krutzsch(1963) suggested an affinity of Retitriletes with spores produced by the Lycopsida ( Lycopodiaceae ), for example Lycopodium Linnaeus.

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.