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Chatangiella verrucosa

Chatangiella verrucosa, (Manum, 1963), Lentin and Williams, 1976

Originally Deflandrea, subsequently Trithyrodinium. thirdly Australiella, fourthly (and now) Chatangiella.
Tax. sr. synonym of Chatangiella vnigrii (Vozzhennikova, 1967) Lentin and Williams, 1976, according to Yun, 1981.

Holotype: Manum 1963: Pl. III, figs. 1, 2
Locus typicus: Graham Island, Arctic Canada
Stratum typicum: Cretaceous
Age: Middle Cretaceous
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Original description as Deflandrea verrucosa: [Manum 1963, p. 60-61]:

Diagnosis:
Theca in dorsoventral view roughly rectangular with a convex equatorial region and divided into nearly equal parts by a slightly spiral, laevo-rotatory girdle. Epitheca widens towards the truncate apex; apical horn almost equilaterally triangular in outline. Hypotheca narrows slightly towards a truncate to concave distal end with a distinct, triangular horn on the left-hand side, and a minute one on the right-hand side.
Intercalary archeopyle hexagonal to trapezium-shaped.
Theca-membrane c. 1 µm thick with warts of very variable size and shape, up to 2 µm high and 6 µm wide; warts largest and most closely spaced equatorially. Girdle bordered by ridges with more or less conspicuous discontinuities. Central portion of theca occupied by a capsule of almost circular outline which touches the theca in the equatorial region, wall c. 2 µm thick and granular.

Dimensions:
Holotype: length 134 µm width 83 µm.
Range: length 112-135 µm, width 65-87 µm. Average of 24 specimens 124x73 µm.

Description:
The broadening of the theca above the upper limit of the capsule forms "shoulders" which usually have angular outlines and straight upper limits, but sometimes they are rounded. The triangular apical horn is about 15 µm long and sometimes has a solid tip.
The larger antapical horn is similar to it in size and outline, and it is usually pointed. The smaller one is indistinct.
The archeopyle is roughly trapezium-shaped with the shorter parallel side proximal to the girdle and the longer one (by 3-4 times) distal to it. The lateral sides, however, are more or less rounded towards their distal ends, thus indicating the basically hexagonal shape of the corresponding plate, with alternating short and long sides. In some specimens this shape is quite distinct.
The warty ornamentation of the theca is usually less dense and finer towards the apex and antapex where there may be scattered granules only, but examples have been observed which were heavily warty all over. The bordering of the girdle sometimes seems to be produced by merging of warts, and usually there are warts in the girdle itself. Some specimens are so heavily ornamented in the equatorial region that the girdle is obscured. In heavily warty specimens the "breaks" in the girdle may be indistinct, but when seen they are in positions corresponding to those in D. scheii and D. sverdrupiana. A longitudinal furrow is suggested by more or less conspicuous longitudinal folds in the hypotheca. The capsule opens by the release of a roughly hexagonal apical portion of the wall; in addition, distinct breaks extend laterally in the wall on either side of the main opening.

Remarks/Comments:
See under D. granulifera.

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Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.

Chatangiella verrucosa (Manum, 1963) Lentin and Williams, 1976, has verrucae of variable shape and size up to 2 µm high and 6 µm wide, ornamentation most closely spaced equatorially. Girdle bordered by discontinuous ridges.
Size: pericyst length 112-135 µm, width 65-87 µm
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