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Chatangiella williamsii
Chatangiella williamsii, Yun, 1981
Holotype: Yun, 1981, pl.13, fig.12, Fensome et al., 1991, fig.2 - p.769
Paratype: Yun, 1981, pl.13, fig.l4.
Locus typicus: Timmermann brickyard near Esbeck, Germany
Stratum typicum: Early Santonian
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Original description: [Yun, 1981, p. 67]: (Translation: Fensome, 1991, p. 769-771):
Diagnosis:
The pentagonal, bicavate cyst has an interrupted paracingulum with bordering ribs, a wide parasulcus, a blunt apical horn and a more strongly developed left antapical horn. The operculum of the periarcheopyle is omegaform and corresponds to paraplate 2a, which remains attached at the H(4) suture.
Description:
The dorsoventrally flattened cyst, with pentagonal outline, is divided into a periepicyst and a perihypocyst of equal size by a 6 µm wide periparacingulum. The periepicyst is in the form of an equilateral triangle. The two bilaterally symmetrical sides have a slight protrusion ("shoulder") at half the epicyst height. Apart from the left antapical horn, the hypocyst is inversely trapezoidal with more or less straight lateral sides.
The slightly helicoidal periparacingulum is characterized by border ribs or by a row of tubercles on both paracingular margins, which are regularly interrupted dorsally.
The periparasulcus is 14 - 18 µm wide and narrows towards both poles.
The distally rounded apical horn is of variable size and cannot be precisely differentiated from the central body. The two antapical horns always differ in size, with the left one being larger and longer. The outline between the two horns is concave.
The transversely ovoidal endocyst is adjacent to the pericyst equatorially with an intervening gap of 1 - 2.5 µm, so that a large pericoel is always developed both in the hypocyst and epicyst.
The intercalary, horseshoe-shaped periarcheopyle is ca. 15 µm wide. The operculum invariably remains attached to the cyst along its posterior margin.
Dimensions:
Holotype: pericyst 54x78 µm, epicyst 30x48 µm, width/length 0.7, transverse archeopyle index 0.46, transverse archeopyle ratio 0.83.
Range: endocyst 27(29.5)30x48(49)51 µm, pericyst 50(53)57x66(74.5)78 µm, width/length (apical horn - right antapical horn) 0.69-0.88, transverse archeopyle index 0.45(0.49)0.52, transverse archeopyle ratio 0.83(0.94)1.06.
Holotype: Yun, 1981, pl.13, fig.12, Fensome et al., 1991, fig.2 - p.769
Paratype: Yun, 1981, pl.13, fig.l4.
Locus typicus: Timmermann brickyard near Esbeck, Germany
Stratum typicum: Early Santonian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Yun, 1981, p. 67]: (Translation: Fensome, 1991, p. 769-771):
Diagnosis:
The pentagonal, bicavate cyst has an interrupted paracingulum with bordering ribs, a wide parasulcus, a blunt apical horn and a more strongly developed left antapical horn. The operculum of the periarcheopyle is omegaform and corresponds to paraplate 2a, which remains attached at the H(4) suture.
Description:
The dorsoventrally flattened cyst, with pentagonal outline, is divided into a periepicyst and a perihypocyst of equal size by a 6 µm wide periparacingulum. The periepicyst is in the form of an equilateral triangle. The two bilaterally symmetrical sides have a slight protrusion ("shoulder") at half the epicyst height. Apart from the left antapical horn, the hypocyst is inversely trapezoidal with more or less straight lateral sides.
The slightly helicoidal periparacingulum is characterized by border ribs or by a row of tubercles on both paracingular margins, which are regularly interrupted dorsally.
The periparasulcus is 14 - 18 µm wide and narrows towards both poles.
The distally rounded apical horn is of variable size and cannot be precisely differentiated from the central body. The two antapical horns always differ in size, with the left one being larger and longer. The outline between the two horns is concave.
The transversely ovoidal endocyst is adjacent to the pericyst equatorially with an intervening gap of 1 - 2.5 µm, so that a large pericoel is always developed both in the hypocyst and epicyst.
The intercalary, horseshoe-shaped periarcheopyle is ca. 15 µm wide. The operculum invariably remains attached to the cyst along its posterior margin.
Dimensions:
Holotype: pericyst 54x78 µm, epicyst 30x48 µm, width/length 0.7, transverse archeopyle index 0.46, transverse archeopyle ratio 0.83.
Range: endocyst 27(29.5)30x48(49)51 µm, pericyst 50(53)57x66(74.5)78 µm, width/length (apical horn - right antapical horn) 0.69-0.88, transverse archeopyle index 0.45(0.49)0.52, transverse archeopyle ratio 0.83(0.94)1.06.