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Endoscrinium velum
From Fensome et al., 2019:
Endoscrinium velum Pestchevitskaya, 2009, p.106,108, pl.1, figs.3–4: text fig.2A. Holotype: Pestchevitskaya, 2009, pl.1, figs.3–4. Age: Berriasian–early Valanginian.
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Original description (Pestchevitskaya, 2009) (translated from Russian):
Endoscrinium velum Pestchevitskaya sp. n.
Plate, figs. 3–4; Fig. 2, A
Origin of the name. From Latin velum (sail), by the shape of the pericyst in the antapical region.
Holotype. Specimen No. 842/135.1–10 CSGM, plate, figs. 3, 4; Nordvik Peninsula, exp. 33, layer 51, sample 51, prep. 135.1; lower Valanginian, Neotollia klimovskiensis Zone.
Diagnosis. Cyst proximate, circumcavate;
endo cyst rounded rhombic in outline, with small prominences in apex and antapex; pericyst follows the shape of endocyst, exept of dorsal side of hypocyst with wide swelling; apical horn short, wide conic, with wide rounded distal end; pericoel narrow, widening in apex and especially in dorsal side of hypocyst; endophragm thick, roughened; periphragm rather thick, transparent, smooth or roughened; paratabulation leptodinioid, expressed by even parasutural ridges; formula: 1pr (Q), 4’, 6’’, 6c, 5s, 6’’’, 1p, 1’’’’; archeopyle precingular, type 1P (3’’).
Material. 3 well-preserved specimens.
Description. The cyst is proximal, circumcavated. The endocyst is rounded-rhombic in shape. In the apical region there is one, and in the antapical region there are two small protuberances. The apical and right antapical are hemispherical, the left antapical is reduced, and therefore has a smoothed shape. The pericyst has a shape similar to the endocyst, with the exception of the dorsal region on the hypocyst, where a wide swelling is formed, like a sail. In the apical region there is a short, wide horn. The shape is conical, the distal end is widely rounded. The pericoel is narrow, widens in the apical region and, especially strongly, on the dorsal side of the hypocyst. The endophragm is dense, shagreen. The periphragm is quite dense, transparent, smooth over most of the surface. The apical horn and antapex are sculptured with fine shagreen. The paratabulation is leptodinioid, expressed by smooth parasutural ribs. Formula 1pr (Q), 4’, 6’’, 6c, 5s, 6’’’, 1p, 1’’’’. Paraplate 1p is small, located ventrally. Paracingulum weakly left-handed. Parasulcus is straight, rather wide. Archaeopile is precingular, type 1P (3’’).
Sizes (μm). Pericyst length - 81-103; width - 61-75; endocyst length - 61-73; width - 49-60; pericoel width (except apex and dorsal side of hypocyst) - 0.5-5; pericoel width on dorsal side of hypocyst - 10-14; length of apical horn - 9-10; width of base 9-11; distal end - 4-4.5.
Variability. The size and width of the pericoel vary.
Comparison. The new species is characterized by an asymmetrical pericoel. The species E. bessebae Below [Below, 1981] is distinguished by a rounded cyst shape, a narrow apical horn, a wide symmetrical pericoel and a thinner periphragm. The species E. galeritum (Deflandre) Vozzhennikova [Vozhennikova, 1967] has a reticular periphragm with a characteristic cingulate fold, as well as a pericoel expanded in the antapical region. Distinctive features of the species E. luridum (Deflandre) Gocht [Guide…, 1986] are a rhombic cyst shape and a wide pericoel. The species E. campanula (Gocht) Vozzhennikova [Vozhennikova, 1967] also has a rhombic cyst. The cingulum is emphasized by a fold of the periphragm, the pericoel is symmetrical, the apical horn is narrower and longer than in the species E. velum.
Location. Nordvik Peninsula, outcrop 33, layers 50–51, lower Valanginian, Neotollia klimovskiensis Zone.
Endoscrinium velum Pestchevitskaya, 2009, p.106,108, pl.1, figs.3–4: text fig.2A. Holotype: Pestchevitskaya, 2009, pl.1, figs.3–4. Age: Berriasian–early Valanginian.
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Original description (Pestchevitskaya, 2009) (translated from Russian):
Endoscrinium velum Pestchevitskaya sp. n.
Plate, figs. 3–4; Fig. 2, A
Origin of the name. From Latin velum (sail), by the shape of the pericyst in the antapical region.
Holotype. Specimen No. 842/135.1–10 CSGM, plate, figs. 3, 4; Nordvik Peninsula, exp. 33, layer 51, sample 51, prep. 135.1; lower Valanginian, Neotollia klimovskiensis Zone.
Diagnosis. Cyst proximate, circumcavate;
endo cyst rounded rhombic in outline, with small prominences in apex and antapex; pericyst follows the shape of endocyst, exept of dorsal side of hypocyst with wide swelling; apical horn short, wide conic, with wide rounded distal end; pericoel narrow, widening in apex and especially in dorsal side of hypocyst; endophragm thick, roughened; periphragm rather thick, transparent, smooth or roughened; paratabulation leptodinioid, expressed by even parasutural ridges; formula: 1pr (Q), 4’, 6’’, 6c, 5s, 6’’’, 1p, 1’’’’; archeopyle precingular, type 1P (3’’).
Material. 3 well-preserved specimens.
Description. The cyst is proximal, circumcavated. The endocyst is rounded-rhombic in shape. In the apical region there is one, and in the antapical region there are two small protuberances. The apical and right antapical are hemispherical, the left antapical is reduced, and therefore has a smoothed shape. The pericyst has a shape similar to the endocyst, with the exception of the dorsal region on the hypocyst, where a wide swelling is formed, like a sail. In the apical region there is a short, wide horn. The shape is conical, the distal end is widely rounded. The pericoel is narrow, widens in the apical region and, especially strongly, on the dorsal side of the hypocyst. The endophragm is dense, shagreen. The periphragm is quite dense, transparent, smooth over most of the surface. The apical horn and antapex are sculptured with fine shagreen. The paratabulation is leptodinioid, expressed by smooth parasutural ribs. Formula 1pr (Q), 4’, 6’’, 6c, 5s, 6’’’, 1p, 1’’’’. Paraplate 1p is small, located ventrally. Paracingulum weakly left-handed. Parasulcus is straight, rather wide. Archaeopile is precingular, type 1P (3’’).
Sizes (μm). Pericyst length - 81-103; width - 61-75; endocyst length - 61-73; width - 49-60; pericoel width (except apex and dorsal side of hypocyst) - 0.5-5; pericoel width on dorsal side of hypocyst - 10-14; length of apical horn - 9-10; width of base 9-11; distal end - 4-4.5.
Variability. The size and width of the pericoel vary.
Comparison. The new species is characterized by an asymmetrical pericoel. The species E. bessebae Below [Below, 1981] is distinguished by a rounded cyst shape, a narrow apical horn, a wide symmetrical pericoel and a thinner periphragm. The species E. galeritum (Deflandre) Vozzhennikova [Vozhennikova, 1967] has a reticular periphragm with a characteristic cingulate fold, as well as a pericoel expanded in the antapical region. Distinctive features of the species E. luridum (Deflandre) Gocht [Guide…, 1986] are a rhombic cyst shape and a wide pericoel. The species E. campanula (Gocht) Vozzhennikova [Vozhennikova, 1967] also has a rhombic cyst. The cingulum is emphasized by a fold of the periphragm, the pericoel is symmetrical, the apical horn is narrower and longer than in the species E. velum.
Location. Nordvik Peninsula, outcrop 33, layers 50–51, lower Valanginian, Neotollia klimovskiensis Zone.