Back
Wetzeliella astra
Wetzeliella astra Costa et al., 1978
Holotype: Costa et al., 1978, text-fig.2
NOW Dracodinium. Originally Wetzeliella, subsequently (and now) Dracodinium.
Locus typicus: Lower London Clay Bean.
Stratum typicum: Ypressian
Age: Early Eocene
synonyms:
1966 Wetzeliella (Wetzeliella) ovalis Eisenack, Williams & Downie, p. 192, pl. 18, fig. 10.
1969 Wetzeliella sp. 1, Gocht, pp. 2t-2, pl. 10, fig. 8;
Original Diagnosis: Costa et al. 1978, p. 263
A species of Wetzeliella with a rounded- pentagonal pericyst produced into five small horns, of which the right antapical horn is strongly reduced. Thin-walled endocyst, separated from the pericyst by a distinct though narrow pericoel. Periphragm bearing abundant hollow intratabular processes, distally open, flaring into 4-7 (usually 6) secae. Peri- and endo-archeopyle subquadrangular, type I/I (2a/2a), the periarcheopyle being slightly more elongate in the axial direction than the endoarcheopyle.
Dimensions. Holotype: pericyst length 100 µm, breadth 98 µm; endocyst length 63 µm, breadth 66 µm; processes length 5-8 µm. Range: pericyst length 105-89 µm, breadth 103-85 µm; endocyst length 65-57 µm, breadth 69-6t µm: processes length 5-8 µm. Specimens measured: 9.
Remarks: Costa et al. 1978, p. 263
W. astra differs from W. aniculala Eisenack in its smaller size, narrower pericoel, denser ornament and strongly asymmetrical outline. W. meckelfeldensis Gocht and W. Iunaris Gocht are larger, have longer horns, and a periarcheopyle distinctly more elongate than the endoarcheopyle. W astra is closely similar in shape to, and presumably derives from, W (Apectodinium) paniculata Costa & Downie. The latter lacks the distinct pericoel of W. astra and the processes do not show the characteristic distal terminations of W astra. W. astra is the oldest typical Wetzeliella known so far and is probably a link between Welzeliella (Wetzeliella) and Wetzeliella (Apectodinium).
Distribution. Lower London Clay, SE England; Unter Eozan 1, Meckelfeld, N Germany; Formation de Varengeville (lower part), Phare d Ailly, near Dieppe, France.
Holotype: Costa et al., 1978, text-fig.2
NOW Dracodinium. Originally Wetzeliella, subsequently (and now) Dracodinium.
Locus typicus: Lower London Clay Bean.
Stratum typicum: Ypressian
Age: Early Eocene
synonyms:
1966 Wetzeliella (Wetzeliella) ovalis Eisenack, Williams & Downie, p. 192, pl. 18, fig. 10.
1969 Wetzeliella sp. 1, Gocht, pp. 2t-2, pl. 10, fig. 8;
Original Diagnosis: Costa et al. 1978, p. 263
A species of Wetzeliella with a rounded- pentagonal pericyst produced into five small horns, of which the right antapical horn is strongly reduced. Thin-walled endocyst, separated from the pericyst by a distinct though narrow pericoel. Periphragm bearing abundant hollow intratabular processes, distally open, flaring into 4-7 (usually 6) secae. Peri- and endo-archeopyle subquadrangular, type I/I (2a/2a), the periarcheopyle being slightly more elongate in the axial direction than the endoarcheopyle.
Dimensions. Holotype: pericyst length 100 µm, breadth 98 µm; endocyst length 63 µm, breadth 66 µm; processes length 5-8 µm. Range: pericyst length 105-89 µm, breadth 103-85 µm; endocyst length 65-57 µm, breadth 69-6t µm: processes length 5-8 µm. Specimens measured: 9.
Remarks: Costa et al. 1978, p. 263
W. astra differs from W. aniculala Eisenack in its smaller size, narrower pericoel, denser ornament and strongly asymmetrical outline. W. meckelfeldensis Gocht and W. Iunaris Gocht are larger, have longer horns, and a periarcheopyle distinctly more elongate than the endoarcheopyle. W astra is closely similar in shape to, and presumably derives from, W (Apectodinium) paniculata Costa & Downie. The latter lacks the distinct pericoel of W. astra and the processes do not show the characteristic distal terminations of W astra. W. astra is the oldest typical Wetzeliella known so far and is probably a link between Welzeliella (Wetzeliella) and Wetzeliella (Apectodinium).
Distribution. Lower London Clay, SE England; Unter Eozan 1, Meckelfeld, N Germany; Formation de Varengeville (lower part), Phare d Ailly, near Dieppe, France.