Palynology of Middle Tertiary lacustrine deposits

260 K. TAKAHASHI & U. lux
PI. 16, figs. 3 - 4 .
Diagnosis: Triporate pollen with a triangular to subcircular contour due to convex
sides and rounded corners. Exine two-layered, 0.7-1.2 ,urn thick, chagrenate to
weakly intrabaculate, commonly crumpled during fossilization. Apertures poroid,
situated at the equatorial corners, 5 - 8,um in diameter.
Measurements: 28 - 29 ,urn X 26 - 27 ,urn in equatorial diameter.
Holotype: PI. 16, fig. 3; 29 X 27 ,urn in eqautorial diameter; exine chagrenate, 1. 2
pm thick; pore large, circular. 5 -5.2 pm in diameter; no. of specimen: Jos I -10
(GN 5330).
Derivation of name: scabrosus (lat. ) = rough.
Remarks: The new species is almost alike TripOropollenites chnosus Partridge (Stover
& Partidge, 1973, p. 269, pI. 21, figs. 6 a-b) from the Late Eocene to Miocene
(Lower Nothofagidites asperus zone-Triporopollenites bellus zone) of Victoria,
Australia, but differs in its smaller size.
Botanical affinity: Unknown.
Genus Cricotriporites Leidelmeyer 1966.
Type species: Cricotriporites guianensis Leidelmeyer 1966.
Cricotriporites anulatus n. sp.
PI. 16, figs. 6 - 7 .
Diagnosis: Triporate pollen of circular to subcircular contour. Exine two-layered,
chagrenate,
I -1.2 pm thick. Pores oval and furnished with both an annulus and
costae pori; size of pore 2. 5- 3 pm in diameter; thickness of annulus 2 - 3 pm.
Measurements: 25 - 26 pm in equatorial diameter.
Holotype: PI. 16, figs. 6 a-b; size 26 X 26 pm in equatorial diameter; exine chagrenate,
I pm thick; pores 2.5 pm in diameter, annulus 3 pm wide; no. of specimen: Jos I
-12 (GN 5332).
Derivation of name: anulatus (lat.) = provided with a ring.
Remarks: The new species is quite similar to Cricotriporites guianensis Leidelmeyer
from the Early Eocene of British Guyana except its somewhat larger size and more
prominent annulus.
Botanical affinity: Unknown.
Cricotriporites nigerianus n. sp.
PI. 16, figs. 10-16; pI. 38, figs. 1 - 2 .