Cycadopites 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 : 115

Cycadopites sp. ( Fig. 13J )

Cycadopites sp. A, Legrand, Palynologie des dépôts Jurassique supérieur et Crétacé inférieur du Japon, et provinces paléofloristiques du sud-est asiatique: 192, pl. XXI, fig. 2 (2009).

OCCURRENCE. — Kimigahama Fm.

DESCRIPTION

Monosulcate pollen grain. Amb ellipsoidal fusiform. A narrow furrow runs longitudinally through the grain, slightly widening at the ends; it can be bordered by folds of the exine (4 to 5 µm wide). The exine is thin (about 1 µm thick) and psilate. Length = 45-50 µm; width = 20-25 µm.

BOTANICAL AFFINITIES

Cycadales or Bennettitales ( Balme 1995). The present Cycadales are distributed in the tropical to subtropical arid regions. The genus Cycadopites is often found associated with coal strata, and the habitat of this group is supposed to have been much more diversified than now ( Singh 1964). Nevertheless, grains of the genus Cycadopites were found in situ in Sahnia Puri ( Pentoxylales , Pentoxylaceae ) (Sukh-Dev 1980) and Lepidopteris Schimper emend. Townrow (Peltaspermales) ( Anderson & Anderson 1983).

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. Burger, 1965 (F, distal polar view, Ashikajima Fm, SEM-II2a; G, distal polar view, Ashikajima Fm, II2c-H32/1; H, tetrad, Ashikajima Fm, SEM-II2a); I, Cycadopites minimus (Cookson, 1947) Pocock, 1970, Ashikajima Fm, II2e-U64; J, Cycadopites sp., Kimigahama Fm, I1a-X30; K, Ephedripites montanaensis Brenner, 1968, Ashikajima Fm, II2c-N35/4h; L, Gnetaceaepollenites sp., Ashikajima Fm, II2a-S47/1a; M, Corollina sp.,tetrad,Kimigahama Fm, I1a-X42; N, O, Incertae sedis sp. 1, group with detail,Ashikajima Fm,SEM-II2a; P, Pterospermella sp., Ashikajima Fm, II2b-O65; Q, Microthyriacites sp., Ashikajima Fm, II2e-R63/4. Scale bars: 10 μm.