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Wigginsiella grandstandica
Wigginsiella grandstandica Lucas-Clark, 1987
Holotype: Lucas-Clark, 1987, pl.1, figs.1–9; Fensome et al., 1995, figs.1–4 — p.1523.
Locus typicus: Dalton Well, the North Slope, Alaska
Stratum typicum: Late Albian
Age: Albian
synonyms:
Genus A, May and Stein, 1979, pl. 14, figs. 1, 2.
New Genus A, May, 1979, pl. 8, figs. 14, 15.
Original description: Lucas-Clark 1987, p. 162, 164: Wigginsiella grandstandica
Medium to large, acavate, biconical, gonyaulacoid cysts with slender apical horn (10-20 µm long) capped by three spines (each 5-10 µm long). Paracingulum marked by prominent flange composed of a lacy, perforate material and surmounted by a single row of 20 to 30 capitate (anchor-shaped) spines arranged in linear groups of 3 or 4 spines. Spines on the cingular flange do not seem to bear a relationship to paratabulation in spite of grouping. A faint ridge, representing the anterior edge of the cingulum, is rarely present. Antapex ornamented with perforate material and 5 to 10 spines with anchor-shaped tips along the perimeter of the antapical paraplate. The two gonal spines at the dorsal corners of the antapical paraplate usually especially prominent (as long as 25 µm). Outline in dorsal-ventral view strongly biconical, with slight antero-lateral angulations (shoulders) at the base of the horn formed by the dorsal apical paraplates. Outline in lateral view biconical to rhomboidal with concave dorsal hypocyst and truncated antapical region. Outline in apical view circular, sulcus indicated only by break in cingularflange. Parasutures usually not clearly indicated. In exceptional specimens, low parasutural ridges, wall thickenings or small pits in the wall partly outline paraplates. Paraplates in the apical and antapical regions may be covered by perforate, lacy ornament. Paratabulation as described for genus. Preapical paraplate P represented by a short, solid, cylindrical "plug" at the tip of the horn between the three spines. The spines, by their positions and relationship to parasutures, appear to be gonal on the triplejunctions of lu/A/P, A/B/P, and B/lu/ P. Small spines (less than 5 µm long) occasionally present elsewhere on the cyst, as in the sulcal region or at the junction of apical and precingular regions, appear to represent paraplate triple junctions.
Dimensions. Maximum length including spines: 70-100 µm. Maximum width including spines: 65- 90 µm. Body about 50-80 µm in length not including spines and horn.
Remarks: Lucas-Clark 1987, p. 162, 164
This highly distinctive form, although previously undescribed, has been used as an upper Albian marker species in Alaska (J. Bennett, H. Haga, F. E. May, and V. D. Wiggins, oral comm., 1982-1984). Its long spines and distinctive, perforate ornament make it recognizable even from a fragment.
Comparison. Wigginsiella grandslandica is distinguished from W. canadensis by having a longer, more slender horn; fewer, larger spines; a more sharply biconical overall shape; less lacy ornament; less obvious parasutures; and less distinct anterior cingular margin.
Holotype: Lucas-Clark, 1987, pl.1, figs.1–9; Fensome et al., 1995, figs.1–4 — p.1523.
Locus typicus: Dalton Well, the North Slope, Alaska
Stratum typicum: Late Albian
Age: Albian
synonyms:
Genus A, May and Stein, 1979, pl. 14, figs. 1, 2.
New Genus A, May, 1979, pl. 8, figs. 14, 15.
Original description: Lucas-Clark 1987, p. 162, 164: Wigginsiella grandstandica
Medium to large, acavate, biconical, gonyaulacoid cysts with slender apical horn (10-20 µm long) capped by three spines (each 5-10 µm long). Paracingulum marked by prominent flange composed of a lacy, perforate material and surmounted by a single row of 20 to 30 capitate (anchor-shaped) spines arranged in linear groups of 3 or 4 spines. Spines on the cingular flange do not seem to bear a relationship to paratabulation in spite of grouping. A faint ridge, representing the anterior edge of the cingulum, is rarely present. Antapex ornamented with perforate material and 5 to 10 spines with anchor-shaped tips along the perimeter of the antapical paraplate. The two gonal spines at the dorsal corners of the antapical paraplate usually especially prominent (as long as 25 µm). Outline in dorsal-ventral view strongly biconical, with slight antero-lateral angulations (shoulders) at the base of the horn formed by the dorsal apical paraplates. Outline in lateral view biconical to rhomboidal with concave dorsal hypocyst and truncated antapical region. Outline in apical view circular, sulcus indicated only by break in cingularflange. Parasutures usually not clearly indicated. In exceptional specimens, low parasutural ridges, wall thickenings or small pits in the wall partly outline paraplates. Paraplates in the apical and antapical regions may be covered by perforate, lacy ornament. Paratabulation as described for genus. Preapical paraplate P represented by a short, solid, cylindrical "plug" at the tip of the horn between the three spines. The spines, by their positions and relationship to parasutures, appear to be gonal on the triplejunctions of lu/A/P, A/B/P, and B/lu/ P. Small spines (less than 5 µm long) occasionally present elsewhere on the cyst, as in the sulcal region or at the junction of apical and precingular regions, appear to represent paraplate triple junctions.
Dimensions. Maximum length including spines: 70-100 µm. Maximum width including spines: 65- 90 µm. Body about 50-80 µm in length not including spines and horn.
Remarks: Lucas-Clark 1987, p. 162, 164
This highly distinctive form, although previously undescribed, has been used as an upper Albian marker species in Alaska (J. Bennett, H. Haga, F. E. May, and V. D. Wiggins, oral comm., 1982-1984). Its long spines and distinctive, perforate ornament make it recognizable even from a fragment.
Comparison. Wigginsiella grandslandica is distinguished from W. canadensis by having a longer, more slender horn; fewer, larger spines; a more sharply biconical overall shape; less lacy ornament; less obvious parasutures; and less distinct anterior cingular margin.