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Crussolia dalei
Crussolia dalei Smelror and Arhus, 1989
Now Evansia. Originally Crussolia, subsequently (and now) Evansia.
Holotype: Smelror and Arhus, 1989, fig.3, A-B
Locus typicus: Kongsoya, Kong Karls Land, Svalbard
Stratum typicum: Late Callovian
Original description: Smelror and Arhus, 1989, p. 42
Proximate dinoflagellate cyst, with endophragm and periphragm separated. Endophragm is relatively thick compared with the thin hyaline periphragm. The cysts are ellipsoidal in outline, i. e. appearing variable pyriform in dorso-ventral view, tapering to an apical horn, antapex generally convex. Possessing more or less clearly expressed parasutural ridges on the periphragm crests; the ridges may be denticulate, more or less serrate, or smooth. The periphragm surface between the parasutural ridges is smooth. Paratabulation is basically gonyaulacoid, but the exact nature of the tabulation pattern is not clearly identified (information is missing on the outline of the 1u plate, on the paracingular - and parasulcal plates, and whether the cyst is quinqueform or sexiform). Paratabulation indicated by Tayler and Evitt notation is shown in Figs. 2A-D. The archeopyle is intercalary, type 3I. The intercalary archeopyle plates are hexagonal in outline, the first and third are approximately equal in size, the central 2a being somewhat larger.
Dimensions: Overall length 75-105 Ám, overall width 50-65 Ám.
Affinities:
Smelror and Aarhuis, 1989, p. 42: Crussolia dalei differs from Crussolia deflandrei in having a smooth endophragm (C. deflandrei was a finely granulate endophragm) and in possessing a gonyaulacoid tabulation on the periphragm. Crussolia dalei appears to be conspecific with the specimen illustrated as Gonyaulacysta jurassica from the Jurassic of Kong Karls Land by Bjµrke (1977: pl. 8, fig. 6) and the specimens illustrated as Gonyaulacysta kunzeviensis from the Late Callovian - Early Kimmeridgian of the Sverdrup Basin by Davies (1983: pl. 4, figs. 1-3).
Now Evansia. Originally Crussolia, subsequently (and now) Evansia.
Holotype: Smelror and Arhus, 1989, fig.3, A-B
Locus typicus: Kongsoya, Kong Karls Land, Svalbard
Stratum typicum: Late Callovian
Original description: Smelror and Arhus, 1989, p. 42
Proximate dinoflagellate cyst, with endophragm and periphragm separated. Endophragm is relatively thick compared with the thin hyaline periphragm. The cysts are ellipsoidal in outline, i. e. appearing variable pyriform in dorso-ventral view, tapering to an apical horn, antapex generally convex. Possessing more or less clearly expressed parasutural ridges on the periphragm crests; the ridges may be denticulate, more or less serrate, or smooth. The periphragm surface between the parasutural ridges is smooth. Paratabulation is basically gonyaulacoid, but the exact nature of the tabulation pattern is not clearly identified (information is missing on the outline of the 1u plate, on the paracingular - and parasulcal plates, and whether the cyst is quinqueform or sexiform). Paratabulation indicated by Tayler and Evitt notation is shown in Figs. 2A-D. The archeopyle is intercalary, type 3I. The intercalary archeopyle plates are hexagonal in outline, the first and third are approximately equal in size, the central 2a being somewhat larger.
Dimensions: Overall length 75-105 Ám, overall width 50-65 Ám.
Affinities:
Smelror and Aarhuis, 1989, p. 42: Crussolia dalei differs from Crussolia deflandrei in having a smooth endophragm (C. deflandrei was a finely granulate endophragm) and in possessing a gonyaulacoid tabulation on the periphragm. Crussolia dalei appears to be conspecific with the specimen illustrated as Gonyaulacysta jurassica from the Jurassic of Kong Karls Land by Bjµrke (1977: pl. 8, fig. 6) and the specimens illustrated as Gonyaulacysta kunzeviensis from the Late Callovian - Early Kimmeridgian of the Sverdrup Basin by Davies (1983: pl. 4, figs. 1-3).