Barremian palynofloras from the Ashikajima and Kimigahama formations (Choshi Group, Outer Zone of south-west Japan)
Author
Legrand, Julien
Author
Pons, Denise
Author
Nishida, Harufumi
Author
Yamada, Toshihiro
text
Geodiversitas
2011
2011-03-31
33
1
87
135
http://dx.doi.org/10.5252/g2011n1a6
journal article
7707
10.5252/g2011n1a6
31ed99a5-9135-40a2-92a4-64217d9de577
1638-9395
4597011
Nodosisporites makotoi
Legrand, Pons, Nishida & Yamada n. sp.
(
Fig. 10
A-F)
Nodosisporites
sp.,
Legrand,
Palynologie des dépôts Jurassique supérieur et Crétacé inférieur du
Japon
, et provinces paléofloristiques du sud-est asiatique
: 166, 167, pl. XIII, figs 1, 2, 4, 7; pl. XIV, fig. 7 (2009).
TYPE MATERIAL
. —
Site II
, horizon 2, slides a, b;
holotype
(
II2
a-L58/2;
Fig. 10A, D
)
;
paratypes
(
II2
b-E56/3, II2b-U33;
Fig. 10B, C, E, F
). Collection de Paléobotanique-UPMC, Paris,
France
.
ETYMOLOGY. — The species is named in honour of Prof. Makoto Nishida, who first studied fossil plants from the Choshi Group.
OCCURRENCE. — Ashikajima and Kimigahama formations.
TYPE
LOCALITY
. — Hatoyama, SE Choshi Peninsula,
Chiba Prefecture
, Japan.
STRATIGRAPHIC HORIZON. — Ashikajima Formation (Barremian).
DIAGNOSIS
Tetrahedral trilete microspore. Amb rounded triangular. Proximal face slightly flattened, with a psilate contact area followed by 1 or 2 muri parallel to the equator. The laesurae are relatively narrow, raised (about
3 µm
), undulating, and extend to the 3/4 of the spore radius or to the equator; they are smooth or ornamented by small spines (
0.5-1 µm
high and
1-3 µm
in basal diameter). Near the apices, 5-6 big spines (
3-5 µm
high) are present. A translucent equatorial zona with a dentate margin can be seen. The exine is cicatricose. The distal face shows 3 sets of 3-4 muri sinuous but parallel to the equator. One of these sets goes on to form a triangle (sometimes, more or less a network) centered on the distal pole (
Fig. 11
). The ornamentation of this form corresponds to the
type
I-A defined by
Krutzsch (1963)
. Equatorial diameter =
40-45 µm
.
REMARKS
Appendicisporites dentimarginatus
Brenner, 1963
shows similarities with
Nodosisporites makotoi
, but lacks spines on the apices.
BOTANICAL AFFINITIES
Schizaeales
,
Anemiaceae (
Dettmann & Clifford 1992
)
. The ornamentation shows similarities with that of
Anemia phyllitidis
(Linnaeus) Swartz
from
Brazil
, figured by
Tryon & Lugardon (1991)
.