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Gochteodinia parvispina
From Fensome et al., 2019:
Gochteodinia parvispina Duxbury, 2018, p.181, pl.10, figs.6–9,13. Holotype: Duxbury, 2018, pl.10, fig.7. Age: early Valanginian.
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Original description Duxbury, 2018:
Plate 10, Figures 6–9, 13
Holotype: Plate 10, Figure 7.
Paratype: Plate 10, Figure 6.
Type Locality: Well 20/01-8 at 6893.70 ft (conventional core
chip), lower Valanginian. Holotype: E.F. U31.0. Paratype: E.F. F27.0.
Derivation of Name: From the Latin parvus, little and spina, thorn – in reference to the surface ornament.
Diagnosis: A large, smooth and fairly thick-walled species, elongate but unusually broad for the genus and with a long, tapering, distally-rounded apical horn. Numerous, evenly-spaced, very short spines, coni or verrucae cover the main body and extend extend onto the apical horn. Tabulation is expressed only by the archeopyle margin, which appears to involve the displacement of two intercalary plates.
Dimensions:
Holotype: Body length – 127 μm.Width – 73 μm.
Paratype: Length – 119 μm. Width – 73 μm.
Overall: Length – 152 (122) 99 μm. Width – 86 (72) 51 μm
Ornament varies in height between 3μm and 5μm.
Specimens Measured: 25.
Remarks: Gochteodinia parvispina Duxbury n. sp. is a very distinctive species, recogniseable even when fragmented. It differs from most other species of this genus in its unusual size (similar to Gochteodinia scytala Duxbury n. sp.) and in possessing evenly-spaced, numerous spines, coni or verrucae. This species and G. scytala n. sp. are also unusually rotund species.
Although G. parvispina n. sp. and G. scytala n. sp. share some characteristics, the two species have different stratigraphic ranges, the first occurring at a higher level than the last, but both are found within the lower Valanginian, Subzone LKP8.2 (text-fig. 10). It is possible, however, that G. parvispina n. sp. developed from G. scytala n. sp. through an increase in the number and a decrease in the height of the surface ornament.
Occurrences of this species are restricted to a short interval so that in individual wells its occurrence is usually restricted to a single sample. A notable exception to this was in well 20/01-11Z, where this species was recorded in four conventional core samples between 9399.60 ft and 9418.50 ft.
Gochteodinia parvispina Duxbury, 2018, p.181, pl.10, figs.6–9,13. Holotype: Duxbury, 2018, pl.10, fig.7. Age: early Valanginian.
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Original description Duxbury, 2018:
Plate 10, Figures 6–9, 13
Holotype: Plate 10, Figure 7.
Paratype: Plate 10, Figure 6.
Type Locality: Well 20/01-8 at 6893.70 ft (conventional core
chip), lower Valanginian. Holotype: E.F. U31.0. Paratype: E.F. F27.0.
Derivation of Name: From the Latin parvus, little and spina, thorn – in reference to the surface ornament.
Diagnosis: A large, smooth and fairly thick-walled species, elongate but unusually broad for the genus and with a long, tapering, distally-rounded apical horn. Numerous, evenly-spaced, very short spines, coni or verrucae cover the main body and extend extend onto the apical horn. Tabulation is expressed only by the archeopyle margin, which appears to involve the displacement of two intercalary plates.
Dimensions:
Holotype: Body length – 127 μm.Width – 73 μm.
Paratype: Length – 119 μm. Width – 73 μm.
Overall: Length – 152 (122) 99 μm. Width – 86 (72) 51 μm
Ornament varies in height between 3μm and 5μm.
Specimens Measured: 25.
Remarks: Gochteodinia parvispina Duxbury n. sp. is a very distinctive species, recogniseable even when fragmented. It differs from most other species of this genus in its unusual size (similar to Gochteodinia scytala Duxbury n. sp.) and in possessing evenly-spaced, numerous spines, coni or verrucae. This species and G. scytala n. sp. are also unusually rotund species.
Although G. parvispina n. sp. and G. scytala n. sp. share some characteristics, the two species have different stratigraphic ranges, the first occurring at a higher level than the last, but both are found within the lower Valanginian, Subzone LKP8.2 (text-fig. 10). It is possible, however, that G. parvispina n. sp. developed from G. scytala n. sp. through an increase in the number and a decrease in the height of the surface ornament.
Occurrences of this species are restricted to a short interval so that in individual wells its occurrence is usually restricted to a single sample. A notable exception to this was in well 20/01-11Z, where this species was recorded in four conventional core samples between 9399.60 ft and 9418.50 ft.