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Cribroperidinium fragile
From Fensome et al., 2019:
Cribroperidinium fragile Duxbury, 2001, p.104–105, fig.6, nos.1–4. Holotype: Duxbury, 2001, fig.6, nos.1–2. Age: early Barremian.
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Original description (Duxbury, 2001):
Cribroperidinium fragilis n. sp.
Holotype: Figures 6.1, 6.2.
Type Locality: Well 13/24a-4 at 5890 ft (ditch cuttings), Early Barremian, E.F. K29.2.
Derivation of Name: From the Latin fragilis, brittle, fragile - in reference to the easily broken nature of this species.
Diagnosis: A very large but thin-walled, spheroidal dinocyst species which possesses a fairly long, fibro-perforate apical projection. The apical
horn is often less well-preserved than the rest of the cyst, and is often lost, exposing an apical pore. The epicyst and hypocyst are of approximately equal length. Typical gonyaulacacean paratabulation is outlined by narrow, low ridges of even height, which are characteristically sinuous, at least in part. The entire cyst is covered by small, evenly-sized verrucae, which are often aligned parallel to paraplate boundaries. The archeopyle is formed by detachment of paraplate 3".
Dimensions: Holotype: Apical horn – 35 pm. Main body - 114 x 106 μm
Overall: Apical horn – 35 (32) 31 μm.
Specimens measured - 2
Main body – 134 (122) 104 x 117 (110) 103 μm
Specimens measured - 5
Comments: Cribroperidinium fragilis n. sp. is a very distinctive species, characterised by its very large size, its low, regular, often sinuous crests and its ornament of low yerrucae. Also, the apical horn appears to be very unusual, being fibro-perforate and generally poorly-preserved; this is often completely absent.
This species is also characterised by its fragility, and is often represented by broken pieces. Nevertheless, the test is sufficiently characteristic for its recognition even in fragments. Other large species of Cribroperidinium NEALE & SARJEANT, 1962 show features similar to some of those displayed by C. fragilis n. sp., but these are generally thicker-walled, more elongate, more robust and with less regular parasutural and intratabular features.
This species is restricted to the Lower Barremian interval, and it is common only in the lowest part of that Sub-stage.
Cribroperidinium fragile Duxbury, 2001, p.104–105, fig.6, nos.1–4. Holotype: Duxbury, 2001, fig.6, nos.1–2. Age: early Barremian.
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Original description (Duxbury, 2001):
Cribroperidinium fragilis n. sp.
Holotype: Figures 6.1, 6.2.
Type Locality: Well 13/24a-4 at 5890 ft (ditch cuttings), Early Barremian, E.F. K29.2.
Derivation of Name: From the Latin fragilis, brittle, fragile - in reference to the easily broken nature of this species.
Diagnosis: A very large but thin-walled, spheroidal dinocyst species which possesses a fairly long, fibro-perforate apical projection. The apical
horn is often less well-preserved than the rest of the cyst, and is often lost, exposing an apical pore. The epicyst and hypocyst are of approximately equal length. Typical gonyaulacacean paratabulation is outlined by narrow, low ridges of even height, which are characteristically sinuous, at least in part. The entire cyst is covered by small, evenly-sized verrucae, which are often aligned parallel to paraplate boundaries. The archeopyle is formed by detachment of paraplate 3".
Dimensions: Holotype: Apical horn – 35 pm. Main body - 114 x 106 μm
Overall: Apical horn – 35 (32) 31 μm.
Specimens measured - 2
Main body – 134 (122) 104 x 117 (110) 103 μm
Specimens measured - 5
Comments: Cribroperidinium fragilis n. sp. is a very distinctive species, characterised by its very large size, its low, regular, often sinuous crests and its ornament of low yerrucae. Also, the apical horn appears to be very unusual, being fibro-perforate and generally poorly-preserved; this is often completely absent.
This species is also characterised by its fragility, and is often represented by broken pieces. Nevertheless, the test is sufficiently characteristic for its recognition even in fragments. Other large species of Cribroperidinium NEALE & SARJEANT, 1962 show features similar to some of those displayed by C. fragilis n. sp., but these are generally thicker-walled, more elongate, more robust and with less regular parasutural and intratabular features.
This species is restricted to the Lower Barremian interval, and it is common only in the lowest part of that Sub-stage.