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Senegalinium iterlaaense
Senegalinium iterlaaense Nøhr-Hansen and Heilmann-Clausen, 2001, p.164,166–168, fig.6, nos.1–6.
Fensome and Williams (2004, p.596) were incorrect in attributing this name to Hansen.
Holotype: Nøhr-Hansen and Heilmann-Clausen, 2001, fig.6, nos.1–3.
Age: middle Danian–early Selandian.
Original description (Nøhr-Hansen and Heilmann-Clausen, 2001):
Senegalinium iterlaaense n. sp..
1975 Deflandea sp. A; De Coninck, fig. 2, L, M, N
1980 Alterbia dilwynensis; hansen, fig 85 (camera lucida drawings)
1985b Senegalinium dilwynense; Hultberg, p. 145, pl. 10, figs. A, B.
1992 Isabelidinium viborgense; Poasecki et al., fig. 6, I-J
1995 Isabelidinium viborgense; Kurita & McIntyre, pl. 1, figs. 9-10
1996 Isabelidinium? viborgense; Nohr-Hansen, pl. 15, figs 11-12
1997a Isabelidinium aff. Viborgense; Nohr-Hansen, pl. 1, figs. 1-2
Origin of name: named after the bay Iterlaa just north of the kangilia section on the north coast of Nuussuaq. Iterlaa is the greenlandiec word for bay (Fig. 1)
Description:
Cyst type: Dorso-ventrally compressed cyst, pericyst subpentagonal. The apical and the two antapical horns are strongly reduced. The antapical horns are almost equal is size and divided by a concave posterior margin. The epicst and the hypocyst are divided by an outbulging, rather broad and deep cingulum, giving rise to deep notches on the lateral margins of the pericyst. The sulcus is deep and extents to the tips of the antapical horns. The epicst is slightly longer than the hypocyst. The endocyst is avoid to spherical.
Wall relationship: The cyst is two-layered, bicavate and composed of a slightly striate/longitudinal folded, almost hyaline pericyst. The striation is often most pronounced in the cingular area, where the striation may give rise to weak denticles on the cingular parasutures. The endocyst is slightly darker than the epicyst.
Tabulation: paratabulation is reflected by the archeopyle and the clum. The anterior and posteriorparasutures of the latter continuous ridges. A wide and deep sulcus is present on the ventral surface. A precingular paraplate, presumably paraplate 4’’, is recognized below or incorporated into the archeopyle. Two postcingular paraplates are recognized; one on each side of the sulcus, presumably paraplates 1’’’and 5’’’
Periarcheopyle: Intercalary (2a) hexagonal, or an intercalary-precingular combination archeopyle (2a, 4’’’, with 4’’ adnate at the posterior margin)
Dimensions:
Holotype: Overall length of pericyst 61 µm, width of pericyst 50 µm, length of endocyst 36 µm, width of endocyst 43 µm.
Minimum, average and maximum dimensions of 9 specimens from Nuussuap – Overall length of pericyst 51 (59.8) 65 µm, width of pericyst 36 (47.1) 52 µm, length of endocyst 27 (31.8) 36 µm, width of endocyst 34 (42) 47 µm.
Minimum, average and maximum dimensions of 5 specimens from Hvallose, Denmark - Overall length of pericyst 48 (52.2) 56 µm, width of pericyst 39 (41.0) 46 µm, length of endocyst 27 (29.4) 33 µm, width of endocyst 29 (31.6) 34 µm.
Comparison: Senegalinium iterlaanense n.sp. resembles to some extent, Senegalinium dilwynense (Cookson & Eisenack 1965b) Stover & Evitt 1978. The latter species differs, however, by having a slightly longer epicyst and a well-developed left antapical horn. The most notable difference is that the cyst is cornucavate due to the sub-pentagonal endocyst which almost fills the pericyst. Senegalinium iterlaaense n.sp. also to some extent resembles Isabelidinium? Viborgense which differs by having a smooth-walled almost pentagonal pericyst without any striation, and two small openings, one near the apex and one in the posterior part of the sulcus.
Fensome and Williams (2004, p.596) were incorrect in attributing this name to Hansen.
Holotype: Nøhr-Hansen and Heilmann-Clausen, 2001, fig.6, nos.1–3.
Age: middle Danian–early Selandian.
Original description (Nøhr-Hansen and Heilmann-Clausen, 2001):
Senegalinium iterlaaense n. sp..
1975 Deflandea sp. A; De Coninck, fig. 2, L, M, N
1980 Alterbia dilwynensis; hansen, fig 85 (camera lucida drawings)
1985b Senegalinium dilwynense; Hultberg, p. 145, pl. 10, figs. A, B.
1992 Isabelidinium viborgense; Poasecki et al., fig. 6, I-J
1995 Isabelidinium viborgense; Kurita & McIntyre, pl. 1, figs. 9-10
1996 Isabelidinium? viborgense; Nohr-Hansen, pl. 15, figs 11-12
1997a Isabelidinium aff. Viborgense; Nohr-Hansen, pl. 1, figs. 1-2
Origin of name: named after the bay Iterlaa just north of the kangilia section on the north coast of Nuussuaq. Iterlaa is the greenlandiec word for bay (Fig. 1)
Description:
Cyst type: Dorso-ventrally compressed cyst, pericyst subpentagonal. The apical and the two antapical horns are strongly reduced. The antapical horns are almost equal is size and divided by a concave posterior margin. The epicst and the hypocyst are divided by an outbulging, rather broad and deep cingulum, giving rise to deep notches on the lateral margins of the pericyst. The sulcus is deep and extents to the tips of the antapical horns. The epicst is slightly longer than the hypocyst. The endocyst is avoid to spherical.
Wall relationship: The cyst is two-layered, bicavate and composed of a slightly striate/longitudinal folded, almost hyaline pericyst. The striation is often most pronounced in the cingular area, where the striation may give rise to weak denticles on the cingular parasutures. The endocyst is slightly darker than the epicyst.
Tabulation: paratabulation is reflected by the archeopyle and the clum. The anterior and posteriorparasutures of the latter continuous ridges. A wide and deep sulcus is present on the ventral surface. A precingular paraplate, presumably paraplate 4’’, is recognized below or incorporated into the archeopyle. Two postcingular paraplates are recognized; one on each side of the sulcus, presumably paraplates 1’’’and 5’’’
Periarcheopyle: Intercalary (2a) hexagonal, or an intercalary-precingular combination archeopyle (2a, 4’’’, with 4’’ adnate at the posterior margin)
Dimensions:
Holotype: Overall length of pericyst 61 µm, width of pericyst 50 µm, length of endocyst 36 µm, width of endocyst 43 µm.
Minimum, average and maximum dimensions of 9 specimens from Nuussuap – Overall length of pericyst 51 (59.8) 65 µm, width of pericyst 36 (47.1) 52 µm, length of endocyst 27 (31.8) 36 µm, width of endocyst 34 (42) 47 µm.
Minimum, average and maximum dimensions of 5 specimens from Hvallose, Denmark - Overall length of pericyst 48 (52.2) 56 µm, width of pericyst 39 (41.0) 46 µm, length of endocyst 27 (29.4) 33 µm, width of endocyst 29 (31.6) 34 µm.
Comparison: Senegalinium iterlaanense n.sp. resembles to some extent, Senegalinium dilwynense (Cookson & Eisenack 1965b) Stover & Evitt 1978. The latter species differs, however, by having a slightly longer epicyst and a well-developed left antapical horn. The most notable difference is that the cyst is cornucavate due to the sub-pentagonal endocyst which almost fills the pericyst. Senegalinium iterlaaense n.sp. also to some extent resembles Isabelidinium? Viborgense which differs by having a smooth-walled almost pentagonal pericyst without any striation, and two small openings, one near the apex and one in the posterior part of the sulcus.