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Cymososphaeridium arcuatum
From Fensome et al., 2019:
Cymososphaeridium arcuatum Duxbury, 2018, p.180, pl.7, figs.11–13. Holotype: Duxbury, 2018, pl.7, fig.13. Age: early Valanginian.
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Original description Duxbury 2018:
Plate 7, Figures 11–13
Cymososphaeridium sp. 1 of Davey 1982, p. 19, pl. 3, figs. 9, 12.
Holotype: Plate 7, Figure 13.
Paratypes: Plate 7, Figures 11, 12.
Type Locality: lower Valanginian, Speeton Clay, Speeton, England.
Holotype: Division D3D E.F. J45.0. Paratypes: Division D3C E.F. L29.0, E. F. M59.1
Derivation of Name: From the Latin arcuatus, bent like a bow, in reference to the distal process terminations of this species.
Diagnosis: A large chorate cyst with a spheroidal main body bearing solid, mesotabular processes which are distinctly vacuolate proximally. Processes occasionally branch medially but typically flare widely distally, forming arcuate structures which can be simple and entire to complex and fenestrate. The archeopyle is tetratabular apical.
Dimensions: Holotype: Main body 56 × 56 μm. Overall 122 ×
132 μm. Overall: Main body 63(50)41 μm × 61(51)41 μm. Overall 127(110)89 μm × 137(115)99 μm.
Specimens Measured: 15.
Remarks: This species is similar to several other large forms assigned by Davey (1982) to his “Systematophora-Oligosphaeridium-Surculosphaeridium complex” and differentiate in his Table 1 (Davey 1982, p. 11). Cymososphaeridium arcuatum n. sp. differs from Cymososphaeridium validum Davey 1982 in lacking complexly branching processes and in having distintly flared and arcuate process terminations. Also, Cymososphaeridium validum typically displays a significant number of deeply furcate processes (Plate 10, Figure 12), a feature rare in Cymososphaeridium arcuatum n. sp. Cymososphaeridium arcuatum is restricted to the early Valanginian at Speeton, ranging between Beds D4Aand D2E .
Cymososphaeridium arcuatum Duxbury, 2018, p.180, pl.7, figs.11–13. Holotype: Duxbury, 2018, pl.7, fig.13. Age: early Valanginian.
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Original description Duxbury 2018:
Plate 7, Figures 11–13
Cymososphaeridium sp. 1 of Davey 1982, p. 19, pl. 3, figs. 9, 12.
Holotype: Plate 7, Figure 13.
Paratypes: Plate 7, Figures 11, 12.
Type Locality: lower Valanginian, Speeton Clay, Speeton, England.
Holotype: Division D3D E.F. J45.0. Paratypes: Division D3C E.F. L29.0, E. F. M59.1
Derivation of Name: From the Latin arcuatus, bent like a bow, in reference to the distal process terminations of this species.
Diagnosis: A large chorate cyst with a spheroidal main body bearing solid, mesotabular processes which are distinctly vacuolate proximally. Processes occasionally branch medially but typically flare widely distally, forming arcuate structures which can be simple and entire to complex and fenestrate. The archeopyle is tetratabular apical.
Dimensions: Holotype: Main body 56 × 56 μm. Overall 122 ×
132 μm. Overall: Main body 63(50)41 μm × 61(51)41 μm. Overall 127(110)89 μm × 137(115)99 μm.
Specimens Measured: 15.
Remarks: This species is similar to several other large forms assigned by Davey (1982) to his “Systematophora-Oligosphaeridium-Surculosphaeridium complex” and differentiate in his Table 1 (Davey 1982, p. 11). Cymososphaeridium arcuatum n. sp. differs from Cymososphaeridium validum Davey 1982 in lacking complexly branching processes and in having distintly flared and arcuate process terminations. Also, Cymososphaeridium validum typically displays a significant number of deeply furcate processes (Plate 10, Figure 12), a feature rare in Cymososphaeridium arcuatum n. sp. Cymososphaeridium arcuatum is restricted to the early Valanginian at Speeton, ranging between Beds D4Aand D2E .