Back
Oligosphaeridium diluculum
Oligosphaeridium diluculum Davey, 1982b, p.14–15, pl.2, figs.1–5.
Holotype: Davey, 1982b, pl.2, figs.1–2; Fauconnier and Masure, 2004, pl.58, figs.1–3.
Age: late Ryazanian–early Valanginian.
Original diagnosis: Davey, 1982, p. 14
Shape: The body is subspherical. Wall: The thin wall is apparently two-layered. The periphragm is smooth and alone forms the processes. Paratabulation: None. Processes: The plate-centred processes vary considerably in size and shape with the larger ones occupying the pre- and postcingular and antapical regions. The processes terminate distally with aculeate and secate Spilles which maybe branched. Minor fenestration mayhe prescnt. One side of the larger processes is often partly lost and in the narrower processes particularly 1", lp and the parasulcal process(es), it may be completelv Iost and these then appear to be solid. The process formula is 4", 6"", 6""", Ip. 1"""", Ips plus 0-Is. Archaeopyle: An apical archaeopyle (Type A) is typically developed.
Original description: Davey, 1982, p. 14
The cyst wall is relatively thin (less than 1µm) and consequently it is often distorted. The processes vary from approximately 1 to 6 µm in stem width with the pre- and postcingular and antapical processes being the largest. The walls of these processes sometimes appear to be fibrous and this may be related to incipient fenestration which is usually best developed, when present, at the bases of the processes. When the proeess stem is short, the rather irregular distal fureations may extend to the body surface.
Holotype: Davey, 1982b, pl.2, figs.1–2; Fauconnier and Masure, 2004, pl.58, figs.1–3.
Age: late Ryazanian–early Valanginian.
Original diagnosis: Davey, 1982, p. 14
Shape: The body is subspherical. Wall: The thin wall is apparently two-layered. The periphragm is smooth and alone forms the processes. Paratabulation: None. Processes: The plate-centred processes vary considerably in size and shape with the larger ones occupying the pre- and postcingular and antapical regions. The processes terminate distally with aculeate and secate Spilles which maybe branched. Minor fenestration mayhe prescnt. One side of the larger processes is often partly lost and in the narrower processes particularly 1", lp and the parasulcal process(es), it may be completelv Iost and these then appear to be solid. The process formula is 4", 6"", 6""", Ip. 1"""", Ips plus 0-Is. Archaeopyle: An apical archaeopyle (Type A) is typically developed.
Original description: Davey, 1982, p. 14
The cyst wall is relatively thin (less than 1µm) and consequently it is often distorted. The processes vary from approximately 1 to 6 µm in stem width with the pre- and postcingular and antapical processes being the largest. The walls of these processes sometimes appear to be fibrous and this may be related to incipient fenestration which is usually best developed, when present, at the bases of the processes. When the proeess stem is short, the rather irregular distal fureations may extend to the body surface.