Back
Votadinium calvum
Votadinium calvum Reid, 1977
Motile equivalent: Peridinium (now Protoperidinium) oblongum (Aurivillius, 1898) Cleve, 1900, according to Reid (1977, p.444).
For a discussion of the nomenclatural validity and legitimacy of this species name, see the discussion under Votadinium.
Holotype: Reid, 1977, pl.2, fig.21; Fensome et al., 1993a, fig.1 — p.1017.
Locus typicus: Dee Estuary, England
Stratum typicum: Holocene
Original diagnosis: Reid, 1977, p.444
Test "heart shaped" with two antapical lobes separated by a shallow antapical depression in dorsoventral view. Trapezoidal in lateral view. Length and breadth almost equal. Wall thin 1 µm and single layered, usually with a smooth surface but surface may be microgranular. Intercalary archeopyle truncating the apex obliquely.
Original description: Reid, 1977, p.444-445
The two sides of the cyst are symmetrical and mirror images. There are no antapical or apical thickenings of the wall and only one specimen showed surface ornamentation in the form of low irregular granae. Careful observation under phase contrast showed "crater-like" pits on many specimens. The operculum may remain attached at the apex and is sixsided with a length: breath ratio of 0.9:1. Short cracks may develop at right angles to the archeopyle suture indicating the position of the precingular plates. The angular flap-like apex that remains after the archeopyle opens may split down the middle to facilitate dehiscence. In many specimens an inner thin hyaline layer enclosing cytoplasm was seen. It is usually retracted from the outer cyst but has a similar shape.
Size: Holotype: 59 x 71 µm. Range of 15 specimens: 54-72 x 74 µm.
Motile equivalent: Peridinium (now Protoperidinium) oblongum (Aurivillius, 1898) Cleve, 1900, according to Reid (1977, p.444).
For a discussion of the nomenclatural validity and legitimacy of this species name, see the discussion under Votadinium.
Holotype: Reid, 1977, pl.2, fig.21; Fensome et al., 1993a, fig.1 — p.1017.
Locus typicus: Dee Estuary, England
Stratum typicum: Holocene
Original diagnosis: Reid, 1977, p.444
Test "heart shaped" with two antapical lobes separated by a shallow antapical depression in dorsoventral view. Trapezoidal in lateral view. Length and breadth almost equal. Wall thin 1 µm and single layered, usually with a smooth surface but surface may be microgranular. Intercalary archeopyle truncating the apex obliquely.
Original description: Reid, 1977, p.444-445
The two sides of the cyst are symmetrical and mirror images. There are no antapical or apical thickenings of the wall and only one specimen showed surface ornamentation in the form of low irregular granae. Careful observation under phase contrast showed "crater-like" pits on many specimens. The operculum may remain attached at the apex and is sixsided with a length: breath ratio of 0.9:1. Short cracks may develop at right angles to the archeopyle suture indicating the position of the precingular plates. The angular flap-like apex that remains after the archeopyle opens may split down the middle to facilitate dehiscence. In many specimens an inner thin hyaline layer enclosing cytoplasm was seen. It is usually retracted from the outer cyst but has a similar shape.
Size: Holotype: 59 x 71 µm. Range of 15 specimens: 54-72 x 74 µm.