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Weiachia sp.
Weiachia sp. Feist-Burkhardt 1995b
Figured in Feist-Burkhardt 1995b: Plate 1, figs. 7, 8, 10, 11
Remarks: Feist-Burkhardt 1995b, p. 214
This form is characterized by a subcircular, teardrop-like endo- and pericyst with a narrower pericoel than in Weiachia fenestrata. The endocyst is slightly asymmetrical, showing a left antapical protuberance. The paracingulum is indicated by folds in the endo- and periphragm. Fenestrae may or may not be developed. Presence or absence of fenestrae is difficult to determine and their recognition may depend on specimen preservation and orientation. The camerate mid-dorsal intercalary paraplate (2a) represents the adnate operculum. The apex on the endocyst is marked by an oval ring-like structure, corresponding probably to the pop paraplate. A flagellar pore imprint is sometimes indicated (Plate 1, fig. 8). The species is not formally described here until further investigation on intraspecific variability is undertaken.
Size. Pericyst: length 33.5 µm - 38 µm, width 25.5 µm - 29 µm. Endocyst: length: 27 µm - 32 µm, width 22.5 µm - 26 µm, Material. 32 Specimens, 5 measured.
Comparison. Weiachia sp. is very similar to Moesiodinium raileanui Antones,cu 1974 but differs in having an adnate rather than free operculum. It differs from W. fenestrata in having an endocyst with a subcircular (teardrop-like) rather than a peridinioid shape.
Occurrence. Late early to late Toarcian (Bifrons to Thouarsense Zones), Switzerland.
Previously Reported Occurrence. Toarcian, Spitsbergen (Bjaerke, 1980, pl. 5, figs. 5, 6, 9 only, as Moesiodinium raileanui Antonescu 1974).
Figured in Feist-Burkhardt 1995b: Plate 1, figs. 7, 8, 10, 11
Remarks: Feist-Burkhardt 1995b, p. 214
This form is characterized by a subcircular, teardrop-like endo- and pericyst with a narrower pericoel than in Weiachia fenestrata. The endocyst is slightly asymmetrical, showing a left antapical protuberance. The paracingulum is indicated by folds in the endo- and periphragm. Fenestrae may or may not be developed. Presence or absence of fenestrae is difficult to determine and their recognition may depend on specimen preservation and orientation. The camerate mid-dorsal intercalary paraplate (2a) represents the adnate operculum. The apex on the endocyst is marked by an oval ring-like structure, corresponding probably to the pop paraplate. A flagellar pore imprint is sometimes indicated (Plate 1, fig. 8). The species is not formally described here until further investigation on intraspecific variability is undertaken.
Size. Pericyst: length 33.5 µm - 38 µm, width 25.5 µm - 29 µm. Endocyst: length: 27 µm - 32 µm, width 22.5 µm - 26 µm, Material. 32 Specimens, 5 measured.
Comparison. Weiachia sp. is very similar to Moesiodinium raileanui Antones,cu 1974 but differs in having an adnate rather than free operculum. It differs from W. fenestrata in having an endocyst with a subcircular (teardrop-like) rather than a peridinioid shape.
Occurrence. Late early to late Toarcian (Bifrons to Thouarsense Zones), Switzerland.
Previously Reported Occurrence. Toarcian, Spitsbergen (Bjaerke, 1980, pl. 5, figs. 5, 6, 9 only, as Moesiodinium raileanui Antonescu 1974).