Palynology of Middle Tertiary lacustrine deposits

Palynology of Middle Tertiary lacustrine deposits
247
Remarks: A single specimen was observed.
Botanical affinity: Unknown CDicotyledonopsida).
Genus Foveotricolporites Pierce 1961.
Type species: Foveotricolporites rhombohedralis Pierce 1961.
Foveotricolporites tenuiexinus n. sp.
PI. 30, figs. 8 - 9; pI. 38, fig. 4.
Diagnosis: Tricolporate pollen grains. Figura spheroidal to subprolate in equatorial
view. Three conspicuous colpi radially symmetrical, converging at the poles. Exine
foveolate; lumina O. 5- 1 ,urn in diameter; muri baculate or tectate, 0.5- 1 ,urn high.
Pores round or equatorially elongated.
Measurements: 36 X 30 - 34 ,urn in size.
Width / length ratio. 0.83-0.94.
Holotype: PI. 30, figs. 9 a - b; size 36 X 30 ,urn; foveolate; lumina 0.5- 1 ,urn in
diameter; muri baculate to tectate, l,um high; width / length ratio: 0.83; no. of
specimen: los 1 -15 (GN 5335).
Derivation of name: tenuis (lat.) = thin, weak; exinus from extimus (lat.) = external,
here external membrane (exine).
Remarks: The new species resembles Foveotricolporites marginatus Gonzalez Guzman, F.
voluminosus Gonzalez Guzman from the Eocene in the Tibli area, Colombia and F.
rhombohedralis Pierce from the Lower Late Cretaceous of Minnesota CU. S. A.),
but differs most of all in its thinner exine, besides that the first has no margo colpi
and the second is larger in size.
Botanical affinity: Unknown (Dicotyledonopsida).
Foveotricolporites sp.
PI. 29, figs. 24a - b.
Description: Tricolporate pollen of broad-ellipsoidal or subprolate shape. Three
distinct colpi converge in radial symmetry at the poles. Sculpture of exine foveolate;
wall two-layered, 2,um thick; ectexine intrarugulate; endexine smooth to chagrenate;
ectexine double as thick as endexine. Pores round and small.
Measurements: 51 X 40 ,urn in size.
Width / length ratio: 0.78.
Remarks: The single specimen encountered is rather large and for the time being not
comparable with other species of the genus.