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Oligosphaeridium trabeculosum
Oligosphaeridium trabeculosum Singh, 1983
Holotype: Singh, 1983, pl.41, fig.11
Locus typicus: Peace River area, Canada
Stratum typicum: Early Cenomanian
Original description: Singh, 1983, p. 122
Skolochorate cysts; central body subspherical, smooth, bearing 18 medium-sized to long, hollow, intratabular processes reflecting a paratabulation formula: 4", 6", 6""", 1p, 1""""; endophragm and periphragm of the central body appressed between the processes; periphragm forming the processes; stems of the processes 1 to 3.5 µm wide; processes widening slightly at the base and open distally; distal ends of the processes slightly expanded and fringed with a few 3- to 5 mm long spines; distal expansions of the processes connected by 0.5- to 1 µm wide, smooth trabeculae; trabeculae not connecting processes across the paracingular zone; processes progressively increasing in length toward the antapex, with the apical ones shortest, the precingular ones longer, and the postcingular and antapical ones longest; postcingular and antapical processes almost twice the length of the apical processes; length of the processes from 1/4 to 2/3 of the diameter of the central body; paracingular zone wide, without processes; archeopyle apical, type tA; operculum free.
Size range: Overall dimension including the processes 86(88)91 µm. Holotype 91 µm. Length of the central body 45(48)51 µm. Holotype 51 µm.
Breadth of the central body 41 (43)45 µm. Holotype 41 µm.
Length of the antapical and postcingular processes 24(27)29 µm. Holotype 24 to 29 µm. Length of the apical processes 14(15)17 µm. Holotype 14 to 16 µm.
Specimens measured 3.
Affinities:
Singh, 1983, p. 123: Oligosphaeridium trabeculosum differs from other species of the genus Oligosphaeridium in having processes which are connected distally by trabeculae and progressively increase in length toward the antapex. The antapical and postcingular processes are almost twice the length of the apical processes.
O. trabeculosum superficially resembles some species of the genus Adnatosphaeridium Williams and Downie, in possessing processes which are connected distally by trabeculae. However, the paratabulation in O. trabeculosum reflected by the intratabular processes is identical to that of the genus Oligosphaeridium. The presence of a wide paracingular zone devoid of processes in this species also favours its assignment to the genus Oligosphaeridium.
Holotype: Singh, 1983, pl.41, fig.11
Locus typicus: Peace River area, Canada
Stratum typicum: Early Cenomanian
Original description: Singh, 1983, p. 122
Skolochorate cysts; central body subspherical, smooth, bearing 18 medium-sized to long, hollow, intratabular processes reflecting a paratabulation formula: 4", 6", 6""", 1p, 1""""; endophragm and periphragm of the central body appressed between the processes; periphragm forming the processes; stems of the processes 1 to 3.5 µm wide; processes widening slightly at the base and open distally; distal ends of the processes slightly expanded and fringed with a few 3- to 5 mm long spines; distal expansions of the processes connected by 0.5- to 1 µm wide, smooth trabeculae; trabeculae not connecting processes across the paracingular zone; processes progressively increasing in length toward the antapex, with the apical ones shortest, the precingular ones longer, and the postcingular and antapical ones longest; postcingular and antapical processes almost twice the length of the apical processes; length of the processes from 1/4 to 2/3 of the diameter of the central body; paracingular zone wide, without processes; archeopyle apical, type tA; operculum free.
Size range: Overall dimension including the processes 86(88)91 µm. Holotype 91 µm. Length of the central body 45(48)51 µm. Holotype 51 µm.
Breadth of the central body 41 (43)45 µm. Holotype 41 µm.
Length of the antapical and postcingular processes 24(27)29 µm. Holotype 24 to 29 µm. Length of the apical processes 14(15)17 µm. Holotype 14 to 16 µm.
Specimens measured 3.
Affinities:
Singh, 1983, p. 123: Oligosphaeridium trabeculosum differs from other species of the genus Oligosphaeridium in having processes which are connected distally by trabeculae and progressively increase in length toward the antapex. The antapical and postcingular processes are almost twice the length of the apical processes.
O. trabeculosum superficially resembles some species of the genus Adnatosphaeridium Williams and Downie, in possessing processes which are connected distally by trabeculae. However, the paratabulation in O. trabeculosum reflected by the intratabular processes is identical to that of the genus Oligosphaeridium. The presence of a wide paracingular zone devoid of processes in this species also favours its assignment to the genus Oligosphaeridium.