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Dodekovia tegillata
From Fensome et al., 2019:
Dodekovia tegillata Prauss, 1989, p.19–20, pl.3, figs.1–6,10–12; text-fig.4. Holotype: Prauss, 1989, pl.3, figs.4–6; text-fig.4. Age: late Toarcian–early Aalenian.
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Original description: [Prauss, 1989] (translated from German):
Plate 3, Figs. 1-6, 10-12; Text Fig. 4
Nominal derivation: tegillum (Latin) small cover, after the characteristic, tegillate wall structure.
Holotype: K1, 2. 6, Plate 3, Fig. 4-6.
Locus typicus: BG SPD 10, 81.80 m.
Stratum typicum: Toarcian, Levesquei zone, calcareous concretion in marl clays, dark.
Description: Cyst habitus proximate/acavate, ambitus almost ideally spheroidal. Essentially nonareate.
Anterior intercalary archeopyle (2a), secant operculum. The geniculate outline of the operculum, typical of Dodekovia, is unclear due to rounding The pedium is solid, and the luxuria forms numerous short columellae that merge distally into a continuous tegillum (Plate 3, Figs. 2, 6, 11). The individual columellae are randomly distributed across the pedium, but in some places they may form a loose, reticulate arrangement with a hexagonal mesh configuration. Isolated columellae are also found within the meshes (Plate 3, Figs. 4-5). In the area around the archeopyle, the luxuria structures are often fused into sutures, representing the finis between 3/4', 3a/4', 4"/3a, and in some cases also 3"/4" (Plate 3, Figs. 4-5, 10). However, these sutures quickly terminate in nonareate areas, which occupy the majority of the cyst surface (Plate 3, Figs. 1, 12).
Dimensions (average): Pedium: 24.4
+ Tegillum: 28.8
Measured individuals: 5
Remarks: Similar to N. plegas (DRUGG 1978) var. brevicornus (see there), a thin, slightly folded, spheroidal sheath was also observed in some cases in the endocoel of the cyst in D. tegillata. In all individuals with this "spore layer," the operculum is still in situ (Plate 3, Figs. 2, 6).
D. tegillata has similarities with D. reticulata BELOW 1987, but differs from it in the formation of a tegillum, areation beginnings around the archeopyle, and only very indistinct reticulation
Occurrence: O'Toarcian to Aalenian, Levesquei to Opalinum Zone.
Dodekovia tegillata Prauss, 1989, p.19–20, pl.3, figs.1–6,10–12; text-fig.4. Holotype: Prauss, 1989, pl.3, figs.4–6; text-fig.4. Age: late Toarcian–early Aalenian.
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Original description: [Prauss, 1989] (translated from German):
Plate 3, Figs. 1-6, 10-12; Text Fig. 4
Nominal derivation: tegillum (Latin) small cover, after the characteristic, tegillate wall structure.
Holotype: K1, 2. 6, Plate 3, Fig. 4-6.
Locus typicus: BG SPD 10, 81.80 m.
Stratum typicum: Toarcian, Levesquei zone, calcareous concretion in marl clays, dark.
Description: Cyst habitus proximate/acavate, ambitus almost ideally spheroidal. Essentially nonareate.
Anterior intercalary archeopyle (2a), secant operculum. The geniculate outline of the operculum, typical of Dodekovia, is unclear due to rounding The pedium is solid, and the luxuria forms numerous short columellae that merge distally into a continuous tegillum (Plate 3, Figs. 2, 6, 11). The individual columellae are randomly distributed across the pedium, but in some places they may form a loose, reticulate arrangement with a hexagonal mesh configuration. Isolated columellae are also found within the meshes (Plate 3, Figs. 4-5). In the area around the archeopyle, the luxuria structures are often fused into sutures, representing the finis between 3/4', 3a/4', 4"/3a, and in some cases also 3"/4" (Plate 3, Figs. 4-5, 10). However, these sutures quickly terminate in nonareate areas, which occupy the majority of the cyst surface (Plate 3, Figs. 1, 12).
Dimensions (average): Pedium: 24.4
+ Tegillum: 28.8
Measured individuals: 5
Remarks: Similar to N. plegas (DRUGG 1978) var. brevicornus (see there), a thin, slightly folded, spheroidal sheath was also observed in some cases in the endocoel of the cyst in D. tegillata. In all individuals with this "spore layer," the operculum is still in situ (Plate 3, Figs. 2, 6).
D. tegillata has similarities with D. reticulata BELOW 1987, but differs from it in the formation of a tegillum, areation beginnings around the archeopyle, and only very indistinct reticulation
Occurrence: O'Toarcian to Aalenian, Levesquei to Opalinum Zone.