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Valvaeodinium scalatum

From Fensome et al., 2019:
Valvaeodinium scalatum (Wille and Gocht, 1979, p.231,233–234, figs.11a–b,12a–b; fig.28, nos.2a–b,3a–c,4a–b,5–6) Below, 1987b, p.74.
Emendation: Below, 1987b, p.74, as Valvaeodinium scalatum.
Holotype: Wille and Gocht, 1979, figs.11a–b; fig.28, nos.2a–b. Originally Comparodinium, subsequently (and now) Valvaeodinium.
Locus typicus: Jebenhausen, Swabian Alb, S Germany
Stratum typicum: Late Pliensbachian

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Translation Wille and Gocht, 1979: LPP

Original diagnosis: Wille and Gocht, 1979, p. 233
Body ellipsoidal to cylindrical, with thin, single-layered wall. Two broad zones (before and behind the cingulum) are characterized by high, longitudinal, ladder-like crests. They consist of rows of slender processes, distally interconnected by a thin deck-beam; the most polar process is always especially thick. The area which is covered with ladders corresponds to the pre- and post-cingular series, the free zone in between to the cingulum. Apical, antapical and intercalary areas are set with strong, blunt thorns. Flagellar marks as two comma-shaped scars within a round, bright court.
Archaeopyle formed by loss of both middorsal apical plates (which would be 3" and 4").
Dimensions: holotype length 35 µm, breadth 24 µm.

Affinities: Wille and Gocht, 1979. p. 234
Only Comparodinium lineatum has ladders, albeit in part of the specimns, and only locally developed. Absolutely as well as relatively, the ladders in C. lineatum are essentially lower and sometimes so narrow, that they can hardly be seen with the light microscope. On the other hand, in C. lineatum the boundaries of the intercalary plates are often indicated by sutural elements.

Emended description: Below, 1987, p. 74
Vesicle/plate arrangement on amphiesma PR, 4", 1a, 5"", 6c, 5""", 1"""", ns. Growth of thecal plates peridinoidal. Cyst proximate, acavate, ellipsoidal to cylindrical with rounded poles, epicyst and hypocyst of equal size; size small; composed of pedium with a smooth or scabrate surface and 20-26 (usually 24) intraareate, longitudinally oriented, scalariform luxuriate pectens in precingular and postcingular locations, and up to 20 large, blunt, peniareate spinules; these ornaments reflect the thecal tabulation: apex with a large spinule to the ventral side marking PR, apicals 1"-4" and anterior intercalary 1a often only partially reflected by low, centrally intraareate verrucae or baculi, but also other short ornaments; PR, 1", 2" and 4" minute compared to the almost apically positioned large opercular areae 3" and 1a, and displaced ventrally; VI 3" (DL), caroidal 1a (DR); 5 steno precingulars of uniform size, each with usually 2 longitud- inally oriented, parallel, scalariform pectens in peniareate positions and one large, blunt, anteriorly intraareate spinule; cingulum planispiral, weakly indented, glabrous or with 6 short, centrally intraareate spinules; sulcus bipartite, anterior sulcus (as) and hypocystal sulcus each with up to 2 peniareate scalariform pectens, posterior portion of the sulcus with a large, intraareate spinule or a group of baculi; 5 steno postcingulars of uniform size, each with usually 2 long, peniareate scalariform pectens parallel to the long axis of the cyst and one large, blunt, posteriorly peniareate spinule near the border of the antapical area; polar VI 1"""" with central intraareate spinule, contours of the antapical plate also reflected schematically by the approximately finate alignment of low granules and individual baculi; archaeopyle in an extremely apical location, apical/ anterior intercalary 3"+1a; operculum solvate, secate, general opercular formula 3"(s)+1a(s).
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