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Nematosphaeropsis grandis
Nematosphaeropsis grandis Davey, 1975
Now Unipontidinium. Oliginally Nematosphaeropsis, subsequently Impagidinium, thirdly (and now) Unipontidinium.
Holotype: Davey, 1975, pl.1, fig.9; Jan du Chêne et al., 1986, pl.55, fig.1-8
Locus typicus: Ghana
Stratum typicum: Senonian (probably Campanian)
Original diagnosis: Davey, 1975, p.153
The cyst is large and spherical, and possesses a thick, densely granular wall. Polar structures are absent. The reflected tabulation, 4", 6", 6c, 5""", 1p, 1"""", ls well defined by sutural crests; along these crests arise rigid processes at more or less regular intervals. Adjacent processes are linked distally by membranous trabeculae. The sutural ornament is noticeably granular. The precingular plate 3" is lost in archaeopyle formation.
DimensionsHolotypeRange
Diameter of central body76x78 Ám56(70)80 Ám
Height of crests12-18 Ám12(15)18 Ám (maxima)
Original description: Davey, 1975, p.153-154
The reflected tabulation exhibited by this species is identical to that of Spiniferites ramosus (Ehrenberg). In extremely rare specimens the trabeculae are reduced or practically absent; these forms are comparable to the genus Spiniferites.
Affinities:
Davey, 1975, p.154: As indicated above the two genera Nematosphaeropsis and Spiniferites are very closely related. N. grandis differs from N. balcombiana Deflandre and Cookson 1955 by its larger size and different crest and trabeculae morphology. The latter species, a Miocene or younger form, is not considered to be directly related to N. grandis.
Now Unipontidinium. Oliginally Nematosphaeropsis, subsequently Impagidinium, thirdly (and now) Unipontidinium.
Holotype: Davey, 1975, pl.1, fig.9; Jan du Chêne et al., 1986, pl.55, fig.1-8
Locus typicus: Ghana
Stratum typicum: Senonian (probably Campanian)
Original diagnosis: Davey, 1975, p.153
The cyst is large and spherical, and possesses a thick, densely granular wall. Polar structures are absent. The reflected tabulation, 4", 6", 6c, 5""", 1p, 1"""", ls well defined by sutural crests; along these crests arise rigid processes at more or less regular intervals. Adjacent processes are linked distally by membranous trabeculae. The sutural ornament is noticeably granular. The precingular plate 3" is lost in archaeopyle formation.
DimensionsHolotypeRange
Diameter of central body76x78 Ám56(70)80 Ám
Height of crests12-18 Ám12(15)18 Ám (maxima)
Original description: Davey, 1975, p.153-154
The reflected tabulation exhibited by this species is identical to that of Spiniferites ramosus (Ehrenberg). In extremely rare specimens the trabeculae are reduced or practically absent; these forms are comparable to the genus Spiniferites.
Affinities:
Davey, 1975, p.154: As indicated above the two genera Nematosphaeropsis and Spiniferites are very closely related. N. grandis differs from N. balcombiana Deflandre and Cookson 1955 by its larger size and different crest and trabeculae morphology. The latter species, a Miocene or younger form, is not considered to be directly related to N. grandis.