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Xenascus esbeckianus
From Fensome et al., 2019:
Xenascus esbeckianus Yun Hyesu, 1981, p.61–62, pl.14, figs.2–4,6.
Holotype: Yun Hyesu, 1981, pl.14, fig.3; Fensome et al., 1991, fig.2 — p.639.
Locus typicus: Timmermann brickyard near Esbeck, Germany
Stratum typicum: Early Santonian
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Translation Yun, 1981: Fensome, 1991, p. 639-641
Original diagnosis: Yun, 1981, p. 63
A species of Xenascus with 5-6 longitudinal ridges on the central body in addition to the wing-like septa of the horns. The central body lacks prominent spines.
Original description: Yun, 1981, p. 63
The cyst consists of a spherical, in places granular endophragm and a thin, smooth periphragm, which gives rise to the processes. The central body is divided into a larger epicyst and a smaller hypocyst by the 7-8 µm wide paracingulum which is weakly indicated on the central body and at the base of the lateral horn. The central body usually displays five, variably developed, low ridges running parallel to the longitudinal axis of the cyst. They may be occasionally interrupted or occur as a row of spines. Only two of these extend from the archeopyle onto the flattened antapical horn. One of the ribs may consist of two antapically converging ridges which connect with a third to form the antapical horn ridge ([Yun Hye-su, 1981] pl.l4, fig.6). The other ridge may run directly from the central body to the antapical horn. As a result, the cross-section of the base of the antapical horn is quadrangular with strongly concave sides. The antapical horn is elongate-triangular in outline and connected to the lateral horn by a pericoel. The dagger-shaped lateral horn is broad-based and in its basal area is bent posteriorly. Proximally it always has an indentation corresponding to the paracingulum. The archeopyle is formed by the removal of an apical cap which measures a third of the central body height.
Xenascus esbeckianus Yun Hyesu, 1981, p.61–62, pl.14, figs.2–4,6.
Holotype: Yun Hyesu, 1981, pl.14, fig.3; Fensome et al., 1991, fig.2 — p.639.
Locus typicus: Timmermann brickyard near Esbeck, Germany
Stratum typicum: Early Santonian
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Translation Yun, 1981: Fensome, 1991, p. 639-641
Original diagnosis: Yun, 1981, p. 63
A species of Xenascus with 5-6 longitudinal ridges on the central body in addition to the wing-like septa of the horns. The central body lacks prominent spines.
Original description: Yun, 1981, p. 63
The cyst consists of a spherical, in places granular endophragm and a thin, smooth periphragm, which gives rise to the processes. The central body is divided into a larger epicyst and a smaller hypocyst by the 7-8 µm wide paracingulum which is weakly indicated on the central body and at the base of the lateral horn. The central body usually displays five, variably developed, low ridges running parallel to the longitudinal axis of the cyst. They may be occasionally interrupted or occur as a row of spines. Only two of these extend from the archeopyle onto the flattened antapical horn. One of the ribs may consist of two antapically converging ridges which connect with a third to form the antapical horn ridge ([Yun Hye-su, 1981] pl.l4, fig.6). The other ridge may run directly from the central body to the antapical horn. As a result, the cross-section of the base of the antapical horn is quadrangular with strongly concave sides. The antapical horn is elongate-triangular in outline and connected to the lateral horn by a pericoel. The dagger-shaped lateral horn is broad-based and in its basal area is bent posteriorly. Proximally it always has an indentation corresponding to the paracingulum. The archeopyle is formed by the removal of an apical cap which measures a third of the central body height.