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Whitecliffia spinosa
Whitecliffia *spinosa (Clarke and Verdier, 1967, p.77–78, pl.17, figs.1–2; text-fig.31) Pearce, 2010, p.68.
Originally Pterospermopsis (Acritarch), subsequently Pterospermella (Acritarch), thirdly Thalassiphora?, fourthly (and now) Whitecliffia.
Taxonomic junior synonym: Hexagonifera perforata (name not validly published), according to Slimani (2001a, p.194).
Holotype: Clarke and Verdier, 1967, pl.17, fig.1.
Age: Santonian.
Original diagnosis: Clarke and Verdier, 1967, p.78: Pterospermopsis spinosa
A species of Pterospermopsis with a small rounded main body and an outer membrane bearing both perforations and spines (echinae). No opening has been observed.
Original description: Clarke and Verdier, 1967, p.78: Pterospermopsis spinosa
The inner body is in contact with the outer membrane only at the apex and antapex giving an equatorial expansion. The main body is smooth. The outer membrane, however, is uniformly sculptured with small perforations. A positive sculpture is also present in the form of spines and short processes with expanded tops again covering the whole of the outer membrane but unlike the perforations they are well separated. No pylome or archaeopyle has so far been seen.
Measurements: Holotype Range
Overall diameter 93 µm 85-100 µm
Inner body diameter 38 µm 35- 50 µm
Length of spines 5-12 µm 3- 18 µm
Affinities:
Clarke and Verdier, 1967, p.78: Pterospermopsis spinosa
P. spinosa differs from all previously described species in the presence of spines on the outer membrane.
Supplementary description (Pearce, 2010). Medium-sized to large, laterally bicavate dinoflagellate cyst. The wall is two-layered comprising a smooth and thin (0.5 μm) endophragm and a smooth to microreticulate or microperforate and thin (0.5 μm) periphragm. The periphragm is in contact towards the apex and antapex and widely separated elsewhere and is ornamented by non-tabular short, thorn-like acuminate spines or rarely by short processes with expanded tops. The endocyst is sub-spherical; the pericyst is sub-circular to ovoidal in plan view and broadly ovoidal in lateral view. The pericoel expands medially, prior to terminating in a rounded margin. A separation in wall layers is also apparent at the apex with the formation of four (or possible more) long, hollow, acuminate processes resembling a crown, and at the antapex with the formation of a wide (w20 μm wide), hollow, distally tapering, tubular process. Spines are also developed on the distal margin of the antapical process. The paracingulum is poorly expressed by two weakly developed ridges, no expression of a parasulcus has been observed. The archaeopyle type is uncertain, possibly remains attached, but may involve the one or more precingular paraplates.
Originally Pterospermopsis (Acritarch), subsequently Pterospermella (Acritarch), thirdly Thalassiphora?, fourthly (and now) Whitecliffia.
Taxonomic junior synonym: Hexagonifera perforata (name not validly published), according to Slimani (2001a, p.194).
Holotype: Clarke and Verdier, 1967, pl.17, fig.1.
Age: Santonian.
Original diagnosis: Clarke and Verdier, 1967, p.78: Pterospermopsis spinosa
A species of Pterospermopsis with a small rounded main body and an outer membrane bearing both perforations and spines (echinae). No opening has been observed.
Original description: Clarke and Verdier, 1967, p.78: Pterospermopsis spinosa
The inner body is in contact with the outer membrane only at the apex and antapex giving an equatorial expansion. The main body is smooth. The outer membrane, however, is uniformly sculptured with small perforations. A positive sculpture is also present in the form of spines and short processes with expanded tops again covering the whole of the outer membrane but unlike the perforations they are well separated. No pylome or archaeopyle has so far been seen.
Measurements: Holotype Range
Overall diameter 93 µm 85-100 µm
Inner body diameter 38 µm 35- 50 µm
Length of spines 5-12 µm 3- 18 µm
Affinities:
Clarke and Verdier, 1967, p.78: Pterospermopsis spinosa
P. spinosa differs from all previously described species in the presence of spines on the outer membrane.
Supplementary description (Pearce, 2010). Medium-sized to large, laterally bicavate dinoflagellate cyst. The wall is two-layered comprising a smooth and thin (0.5 μm) endophragm and a smooth to microreticulate or microperforate and thin (0.5 μm) periphragm. The periphragm is in contact towards the apex and antapex and widely separated elsewhere and is ornamented by non-tabular short, thorn-like acuminate spines or rarely by short processes with expanded tops. The endocyst is sub-spherical; the pericyst is sub-circular to ovoidal in plan view and broadly ovoidal in lateral view. The pericoel expands medially, prior to terminating in a rounded margin. A separation in wall layers is also apparent at the apex with the formation of four (or possible more) long, hollow, acuminate processes resembling a crown, and at the antapex with the formation of a wide (w20 μm wide), hollow, distally tapering, tubular process. Spines are also developed on the distal margin of the antapical process. The paracingulum is poorly expressed by two weakly developed ridges, no expression of a parasulcus has been observed. The archaeopyle type is uncertain, possibly remains attached, but may involve the one or more precingular paraplates.