56
2 Systematic Descriptions
Remarks and comparison: Neoraistrickia ramosa is distinguished from the type
species by the irregularity of the shape and distribution of sculpture. Species
closely resembling Neoraistrickia ramosa were described by Bharadwaj and Salujha under the genus Horriditriletes. The present study treats Neoraistrickia as
synonymous with Horriditriletes, but retains the name ‘Neoraistrickia’. Horriditriletes ramosus was reported from the Permian of Cuhuparbita and Hura Basins
in East India (Banerjee and D’Rozario 1990).
Turma: MONOLETES (Ibrahim 1933).
Genus Laevigatosporites (Ibrahim 1933).
Diagnosis: Amb oval to sub-circular. Monolete; simple laesurae. Exine smooth
to intra-punctate.
Known distribution: Upper Carboniferous to Tertiary of Southern and Northern
hemisphere.
Discussion: Laevigatosporites is distinguished from other monolete spores mainly
by its smooth to almost smooth exine, and simple monolete scar.
Laevigatosporites was established by Potonie and Kremp (1954) for monolete
more or less smooth, oval to sub-circular spores. Potonie and Kremp designated
Laevigatosporites latus Kosanke (1950) as type species for Latosporites. However, Laevigatosporites latus as described by Kosanke fits perfectly into Laevigatosporites Ibrahim. The difference noted by Potonie and Kremp is in the outline,
being more sub-circular than oval in Latosporites, and having less inflated distal
face than in Laevigatosporites. However, the convexity of the distal face is rarely
determinable, since most specimens are compressed in the equatorial plane and
are observed in polar view only. The outline of Laevigatosporites is not considered
by the present author as being a distinct enough feature to justify the separation
of the two genera.
Monolete smooth spores resembling Laevigatosporites were separated from sporangia of Bowmanites bifurcates by Andrews and Mamay (1951) and attributed
to the Sphenopsidae. Similar spores were also isolated from sporangia of
Ptychocarpus unitus (Remy 1957).
Laevigatosporites colliensis (Balme and Hennelly 1956) (Fig. 2.40).
Occurrence: Uncommon. Occurs occasionally in Artinskian to Upper Permian
samples from Collie–Muja Basin.
Description: Monolete. Amb oval to sub-circular. Outline smooth. Laesurae simple, extending to almost whole length of spore; usually followed by folds. Exine
smooth and thin, less than 1 µ.
Dimensions: Length: 54–69 µ; width: 30–54 µ (15 specimens measured).
Remarks and comparisons: Laevigatosporites colliensis is distinguished mainly
by its thin, smooth exine. L. colliensis has been recorded and illustrated from
Collie Basin by Backhouse (1991). Backhouse presented a similar argument as
outlined above, namely that L. colliensis “is presented in a variety of compressional positions at all levels within its range and there seems to be no sound
reason for regarding transversely folded specimen as a separate species.”
2 Systematic Descriptions
Remarks and comparison: Neoraistrickia ramosa is distinguished from the type
species by the irregularity of the shape and distribution of sculpture. Species
closely resembling Neoraistrickia ramosa were described by Bharadwaj and Salujha under the genus Horriditriletes. The present study treats Neoraistrickia as
synonymous with Horriditriletes, but retains the name ‘Neoraistrickia’. Horriditriletes ramosus was reported from the Permian of Cuhuparbita and Hura Basins
in East India (Banerjee and D’Rozario 1990).
Turma: MONOLETES (Ibrahim 1933).
Genus Laevigatosporites (Ibrahim 1933).
Diagnosis: Amb oval to sub-circular. Monolete; simple laesurae. Exine smooth
to intra-punctate.
Known distribution: Upper Carboniferous to Tertiary of Southern and Northern
hemisphere.
Discussion: Laevigatosporites is distinguished from other monolete spores mainly
by its smooth to almost smooth exine, and simple monolete scar.
Laevigatosporites was established by Potonie and Kremp (1954) for monolete
more or less smooth, oval to sub-circular spores. Potonie and Kremp designated
Laevigatosporites latus Kosanke (1950) as type species for Latosporites. However, Laevigatosporites latus as described by Kosanke fits perfectly into Laevigatosporites Ibrahim. The difference noted by Potonie and Kremp is in the outline,
being more sub-circular than oval in Latosporites, and having less inflated distal
face than in Laevigatosporites. However, the convexity of the distal face is rarely
determinable, since most specimens are compressed in the equatorial plane and
are observed in polar view only. The outline of Laevigatosporites is not considered
by the present author as being a distinct enough feature to justify the separation
of the two genera.
Monolete smooth spores resembling Laevigatosporites were separated from sporangia of Bowmanites bifurcates by Andrews and Mamay (1951) and attributed
to the Sphenopsidae. Similar spores were also isolated from sporangia of
Ptychocarpus unitus (Remy 1957).
Laevigatosporites colliensis (Balme and Hennelly 1956) (Fig. 2.40).
Occurrence: Uncommon. Occurs occasionally in Artinskian to Upper Permian
samples from Collie–Muja Basin.
Description: Monolete. Amb oval to sub-circular. Outline smooth. Laesurae simple, extending to almost whole length of spore; usually followed by folds. Exine
smooth and thin, less than 1 µ.
Dimensions: Length: 54–69 µ; width: 30–54 µ (15 specimens measured).
Remarks and comparisons: Laevigatosporites colliensis is distinguished mainly
by its thin, smooth exine. L. colliensis has been recorded and illustrated from
Collie Basin by Backhouse (1991). Backhouse presented a similar argument as
outlined above, namely that L. colliensis “is presented in a variety of compressional positions at all levels within its range and there seems to be no sound
reason for regarding transversely folded specimen as a separate species.”