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Canningia inconspicua
From Fensome et al., 2019:
Canningia inconspicua (Duxbury, 1983, p.32–33, pl.3, fig.6) Fensome et al., 2019a, p.25.
Holotype: Duxbury, 1983, pl.3, fig.6; Fauconnier and Masure, 2004, pl.17, fig.7; Fensome et al., 2019a, fig.12P.
Originally Cyclonephelium, subsequently (and now) Canningia.
Age: late Aptian.
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Cyclonephelium inconspicnum Duxbury, 1983
Holotype: Duxbury, 1983, pl.3, fig.6
Locus typicus: Compton Bay section, Isle of Wight, England
Stratum typicum: Late Aptian
Original diagnosis: Duxbury, 1983, p. 32
A species of Cyclonephelium which is roughly circular in outline but which possesses a left antapical projection. Ornament of a most distinctive nature is present around the dorsal and ventral periphery (mostly dorsal) and this takes the form of a punctate/microreticulate layer which is attached to the cyst by very short rods (approximately 1 Ám in height). Local increases in ornament height are apparent above the left antapical bulge and to the right of this. Where the ornament height increases, the microreticulum becomes more open. Paratabulation is lacking but six precingular paraplates may be inferred from parasutural splits around the apical archeopyle margin. The parasulcus if offset to the left.
Observed Dimensions: Holotype 58x64 µm. Complete specimens 75(70)64x73(67)64 µm. Operculum detached 61(58)49x73(67)58 µm.
Affinities:
Duxbury, 1983, p. 33: The species most comparable with C. inconspicuum are C. vannophorum Davey, 1969 and C. intonsum Duxbury C. inconspicuum differs from C. vannophorum in possessing a punctate/microreticulate layer which is separated from the cyst by very short rods, as opposed to the very irregular, spinose ornament of C. vannophorum which is variously connected along its length.
The body ornament of C. intonsum is very low but is nevertheless distally free. Whatever microreticulation may be observed is produced by lateral fusion of individual elements rather than distal fusion. Further, the ornament of C. intonsum is almost exclusively confined to the ventral surface whereas that of C. inconspicuum is on both surfaces, particularly the dorsal.
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Comments Fensome et al., 2019a:
Duxbury (Citation1983, p. 811) noted that this species has most distinctive [ornament] … around the dorsal and ventral periphery … [in the form of] a punctate/microreticulate layer which is attached to the cyst [sic] by very short rods (approximately 1 μm in height). Local increases in ornament height are apparent above the left antapical bulge and to the left of this [i.e. reflecting asymmetrical antapical prominences].
Duxbury (Citation1983) compared this species with Cyclonephelium (now Aptea?) vannophorum and Cyclonephelium intonsum. However, neither of these species have a periphragm (Duxbury’s ‘punctate/microreticulate layer’), the presence of which leads us to transfer this species to Canningia. The periphragm in Canningia inconspicua is far less continuous than in Canningia reticulata and the reticulum is relatively poorly and inconsistently developed.
Stratigraphical occurrence. Duxbury (Citation1983) described Canningia inconspicua (as Cyclonephelium inconspicuum) from the upper Aptian of southern England.
Canningia inconspicua (Duxbury, 1983, p.32–33, pl.3, fig.6) Fensome et al., 2019a, p.25.
Holotype: Duxbury, 1983, pl.3, fig.6; Fauconnier and Masure, 2004, pl.17, fig.7; Fensome et al., 2019a, fig.12P.
Originally Cyclonephelium, subsequently (and now) Canningia.
Age: late Aptian.
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Cyclonephelium inconspicnum Duxbury, 1983
Holotype: Duxbury, 1983, pl.3, fig.6
Locus typicus: Compton Bay section, Isle of Wight, England
Stratum typicum: Late Aptian
Original diagnosis: Duxbury, 1983, p. 32
A species of Cyclonephelium which is roughly circular in outline but which possesses a left antapical projection. Ornament of a most distinctive nature is present around the dorsal and ventral periphery (mostly dorsal) and this takes the form of a punctate/microreticulate layer which is attached to the cyst by very short rods (approximately 1 Ám in height). Local increases in ornament height are apparent above the left antapical bulge and to the right of this. Where the ornament height increases, the microreticulum becomes more open. Paratabulation is lacking but six precingular paraplates may be inferred from parasutural splits around the apical archeopyle margin. The parasulcus if offset to the left.
Observed Dimensions: Holotype 58x64 µm. Complete specimens 75(70)64x73(67)64 µm. Operculum detached 61(58)49x73(67)58 µm.
Affinities:
Duxbury, 1983, p. 33: The species most comparable with C. inconspicuum are C. vannophorum Davey, 1969 and C. intonsum Duxbury C. inconspicuum differs from C. vannophorum in possessing a punctate/microreticulate layer which is separated from the cyst by very short rods, as opposed to the very irregular, spinose ornament of C. vannophorum which is variously connected along its length.
The body ornament of C. intonsum is very low but is nevertheless distally free. Whatever microreticulation may be observed is produced by lateral fusion of individual elements rather than distal fusion. Further, the ornament of C. intonsum is almost exclusively confined to the ventral surface whereas that of C. inconspicuum is on both surfaces, particularly the dorsal.
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Comments Fensome et al., 2019a:
Duxbury (Citation1983, p. 811) noted that this species has most distinctive [ornament] … around the dorsal and ventral periphery … [in the form of] a punctate/microreticulate layer which is attached to the cyst [sic] by very short rods (approximately 1 μm in height). Local increases in ornament height are apparent above the left antapical bulge and to the left of this [i.e. reflecting asymmetrical antapical prominences].
Duxbury (Citation1983) compared this species with Cyclonephelium (now Aptea?) vannophorum and Cyclonephelium intonsum. However, neither of these species have a periphragm (Duxbury’s ‘punctate/microreticulate layer’), the presence of which leads us to transfer this species to Canningia. The periphragm in Canningia inconspicua is far less continuous than in Canningia reticulata and the reticulum is relatively poorly and inconsistently developed.
Stratigraphical occurrence. Duxbury (Citation1983) described Canningia inconspicua (as Cyclonephelium inconspicuum) from the upper Aptian of southern England.