Converrucosisporites sp.

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 : 92

Converrucosisporites sp.

( Fig. 5N, O )

Converrucosisporites sp. A, Legrand, Palynologie des dépôts Jurassique supérieur et Crétacé inférieur du Japon, et provinces paléofloristiques du sud-est asiatique: 136, pl. III, fig. 2 (2009).

OCCURRENCE. — Ashikajima Fm (rare).

DESCRIPTION

Trilete microspore. Amb rounded triangular. The laesurae are long, rather indistinct, and seem to extend to the 3/4 of the spore radius. The two faces are covered by rounded verrucae of various sizes (0.5 to 3 µm high and 1 to 6 µm in diameter), distributed side by side or sometimes contiguous. Near the equator, some elongated verrucae can be sparsely observed. The exine is about 0.5 µm thick. Equatorial diameter = 30-35 µm.

BOTANICAL AFFINITIES

Cyatheales ?

Figures

FIG. 5. — Spores from the Barremian of south-west Japan: A, B, Biretisporites potoniaei (Delcourt & Sprumont, 1955) Delcourt, Dettmann & Hughes, 1963 (A, proximal face, Ashikajima Fm, II2a-U31/3; B, proximal face, Kimigahama Fm, SEM-I1a); C, Todisporites miser Takahashi,1988, proximal face, Ashikajima Fm, II2b-R25hg; D, Todisporites major Couper, 1958, proximal face,Ashikajima Fm, II2c-H34/1; E, Incertae sedis in Hasenboehler (1981), proximal face, Ashikajima Fm, II2a-Q62/3; F, Cyathidites minor Couper, 1953, proximal face, Ashikajima Fm, IIa-V64; G, Cyathidites australis Couper, 1953, proximal face, Ashikajima Fm, SEM-II2a; H, Cyathidites rarus (Bolkhovitina, 1953) Deák, 1964, proximal face, Ashikajima Fm, II2a-G59/1; I, J, Verrucosisporites densus (Bolkhovitina, 1956) Pocock, 1970, proximal and distal faces, Ashikajima Fm, II2h-H49g; K, Concavissimisporites variverrucatus (Couper, 1958) Brenner, 1963,proximal face,Ashikajima Fm,II2c-K43-1;L, Osmundacidites wellmanii Couper,1953,proximal face,Ashikajima Fm, II2b-P32/4; M, Trilites bossus Couper,1958,Ashikajima Fm,II2f-H29/1; N, O, Converrucosisporites sp.(N, Ashikajima Fm,II2f-V27/3;O, Ashikajima Fm, SEM-II2c); P, Cibotiumspora paradoxa (Maljavkina, 1949) Chang, 1965, proximal face, Kimigahama Fm, I1a-F40-g; Q, Concavissimisporites punctatus (Delcourt & Sprumont, 1955) Brenner, 1963, proximal face, Ashikajima Fm, SEM-II2c. Scale bar: 10 μm.