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Dingodinium cooksoniae
Dingodinium? cooksonii Pocock, 1972
Originally Dingodinium, subsequently (and now) Dingodinium?. Jansonius, 1986, questionably included this species in Dingodinium.
Holotype: Pocock, 1972, pl.23, fig.9; Jansonius, 1986, pl.5, figs.4-5, text-fig.7
Locus typicus: Royalite DeWinton, Western Canada
Stratum typicum: Oxfordian-Kimmeridgian
Original descrpition: Pocock, 1972, p.99
Vesicle ovoid, equatorial section circular; epitheca hemispherical, extended at the apex to form a hollow horn which may be 3.0-4.0 Ám long and rounded at the tip, or may be only 1.5-2.0 Ám long and flattened; hypotheca hemispherical, antapex flattened, the outer layer extended to form two unequal, not very well defined lobes which represent reduced antapical horns; transverse girdle well defined, bounded on the outer edges by distinct folds; longitudinal girdle not detectable and plating not visible; capsule smoothly ovoid to pear-shaped, covered with closely crowded conical processes about 3.0 Ám high, rising from bases 2.0-2.5 Ám in diameter, disposed radially over the capsule, the spacing being very regular and even; capsule about 1.5 Ám thick, enveloped in a smooth membranous outer layer less than 0.5Á thick; capsule pale brown to yellow; outer layer colourless; size range 51.0(64.3)78.0x36.0(51.3)69.0 Ám.
Supplemental descirption: Jansonius, 1986, p.206-207
(Holotype) Pale brown inner body, rather loosely enveloped by a nearly hyaline outer layer. Inner body very broadly elliptical, nearly subcircular (52 x 46 Ám without sculpture), with broadly rounded apex and antapex, wall almost 1.0 Ám thick, but thinner at apex, ornamented by irregularly distributed, but fairly closely spaced flat verrucae, a number of which are raised to form broad based, solid spines with rounded, truncated, or expanded distal ends. Some of these verrucae are aligned, and even fused to some extent, along linear patterns that appear to correspond to a peridinioid paratabulation. A rounded area is delineated by a groove (in part gaping) and apparently represents a large 2a archeopyle, in near apical position. From this groove a number of accessory sutures branch off in a pattern suggesting precingular plates. Because the verrucate sculpture obliterates the vague indications of sutures, only the uppermost (i.e. dorsal) features can be surmised; they are indicated in Text-Figure 7. The cingulum is delineated by rows of fused verrucae, but shows little depression on the outline.
Outer layer ca 0.3 Ám thick, loosely enveloping the hypocyst, showing a tendency to form two antapical lobes. Although the larger spines occur in the hypocyst, they do not, or only incidentally, support the outer layer. The pericoel is strongly reduced in the precingular region, where the outer layer is tightly drawn over the verrucae of the inner body. However, in the apical region a generous pericoel is developed; the apical part (horn?) of the outer layer is lacking, the irregular boundary suggesting that it may have broken off. On the outer layer no indication of paratabulation can be discerned, not even of a cingulum.
Affinities:
Jansonius, 1986, p.207: In Chlamydophorella (=Gardodinium) the tips of the baculate sculpture of the inner cyst are fused with the outer layer. It would seem that the asymmetrical position of the inner body in some forms of Dingodinium results from compression in lateral aspect. Whereas most species of Dingodinium are compressed in lateral (asymmetrical) aspect, D.? cooksoniae appears to have been preserved in dorsoventral comnression.
Originally Dingodinium, subsequently (and now) Dingodinium?. Jansonius, 1986, questionably included this species in Dingodinium.
Holotype: Pocock, 1972, pl.23, fig.9; Jansonius, 1986, pl.5, figs.4-5, text-fig.7
Locus typicus: Royalite DeWinton, Western Canada
Stratum typicum: Oxfordian-Kimmeridgian
Original descrpition: Pocock, 1972, p.99
Vesicle ovoid, equatorial section circular; epitheca hemispherical, extended at the apex to form a hollow horn which may be 3.0-4.0 Ám long and rounded at the tip, or may be only 1.5-2.0 Ám long and flattened; hypotheca hemispherical, antapex flattened, the outer layer extended to form two unequal, not very well defined lobes which represent reduced antapical horns; transverse girdle well defined, bounded on the outer edges by distinct folds; longitudinal girdle not detectable and plating not visible; capsule smoothly ovoid to pear-shaped, covered with closely crowded conical processes about 3.0 Ám high, rising from bases 2.0-2.5 Ám in diameter, disposed radially over the capsule, the spacing being very regular and even; capsule about 1.5 Ám thick, enveloped in a smooth membranous outer layer less than 0.5Á thick; capsule pale brown to yellow; outer layer colourless; size range 51.0(64.3)78.0x36.0(51.3)69.0 Ám.
Supplemental descirption: Jansonius, 1986, p.206-207
(Holotype) Pale brown inner body, rather loosely enveloped by a nearly hyaline outer layer. Inner body very broadly elliptical, nearly subcircular (52 x 46 Ám without sculpture), with broadly rounded apex and antapex, wall almost 1.0 Ám thick, but thinner at apex, ornamented by irregularly distributed, but fairly closely spaced flat verrucae, a number of which are raised to form broad based, solid spines with rounded, truncated, or expanded distal ends. Some of these verrucae are aligned, and even fused to some extent, along linear patterns that appear to correspond to a peridinioid paratabulation. A rounded area is delineated by a groove (in part gaping) and apparently represents a large 2a archeopyle, in near apical position. From this groove a number of accessory sutures branch off in a pattern suggesting precingular plates. Because the verrucate sculpture obliterates the vague indications of sutures, only the uppermost (i.e. dorsal) features can be surmised; they are indicated in Text-Figure 7. The cingulum is delineated by rows of fused verrucae, but shows little depression on the outline.
Outer layer ca 0.3 Ám thick, loosely enveloping the hypocyst, showing a tendency to form two antapical lobes. Although the larger spines occur in the hypocyst, they do not, or only incidentally, support the outer layer. The pericoel is strongly reduced in the precingular region, where the outer layer is tightly drawn over the verrucae of the inner body. However, in the apical region a generous pericoel is developed; the apical part (horn?) of the outer layer is lacking, the irregular boundary suggesting that it may have broken off. On the outer layer no indication of paratabulation can be discerned, not even of a cingulum.
Affinities:
Jansonius, 1986, p.207: In Chlamydophorella (=Gardodinium) the tips of the baculate sculpture of the inner cyst are fused with the outer layer. It would seem that the asymmetrical position of the inner body in some forms of Dingodinium results from compression in lateral aspect. Whereas most species of Dingodinium are compressed in lateral (asymmetrical) aspect, D.? cooksoniae appears to have been preserved in dorsoventral comnression.