Pterospermella, Eisenack, 1972

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 : 116-117

Pterospermella sp. ( Fig. 13P )

OCCURRENCE. — Ashikajima Fm (rare).

DISTRIBUTION. — This genus is known from the Precambrian to possibly Holocene.

DESCRIPTION

Flattened lenticular body. The central body is biconvex and darker than the folded equatorial membrane that surrounds it. Length = 38 µm; width = 30 µm; central body (length × width) = 15 × 10 µm; equatorial membrane width = 10 µm.

Ashikajima Fm Kimigahama Fm

1 % 1 % 23 36 % 4 % 7 % 9 % % 1 % 2 % 12 % 12 % Psilate spores Bisaccate pollen grains Araucariaceae Cicatricose spores Monosulcate pollen grains Other gymnosperms Other ornamented spores Classopollis-Corollina Dinoflagellates

BOTANICAL AFFINITIES

Pterospermatales, Pterospermellaceae of marine environment.

Figures

FIG. 13. — Pollen grains, alga and fungus from the Barremian of south-west Japan: A, Pityosporites sp. cf. P. constrictus Singh, 1964, lateral view, Ashikajima Fm, II2b-J34/1; B, Alisporites thomasii (Couper, 1958) Pocock, 1962, polar view, Ashikajima Fm, II2b-O42/3; C, Incertae sedis sp. 2, Ashikajima Fm, II2c-W65/4; D, Balmeiopsis limbatus (Balme, 1957) Archangelsky, 1977, Ashikajima Fm, II2d- N41/2; E, Inaperturopollenites sp., Kimigahama Fm, I1b-U64/4; F-H, Classopollis torosus (Reissinger, 1950) Couper, 1958 emend.