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Arcticacysta backmanii
From Fensome et al., 2019:
Arcticacysta backmanii Sangiorgi et al., 2009, p.254–255, pl.1, figs.1–12, pl.2, figs.1–9, pl.3, figs.1–2. Holotype: Sangiorgi et al., 2009, pl.1, figs.1–3. Age: ?Early Miocene.
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Original description: [Sangiorgi et al., 2009]:
Diagnosis:
a species of Arcticacysta with a wall ornamented with very low ridges (less than 0.2 µm) which connect to form a microreticulum (details in Plate 1, Fig. 6 and Plate 2, Fig. 9).
The archeopyle, when developed, is of type 3A3I (Plate 1, Figs. 1-5; Plate 2, Figs. 1-5), resulting from the loss of three apical (2’-4’) and three intercalaries (1a-3a).
The sulcus and the cingulum are not indicated, although orientation to the ventral surface is provided by the first apical plate, when clearly visible (Plate 1, Figs. 1-5, Figs 7-8; Plate 2, Figs. 1-5).
Dimensions:
Holotype length 59 µm (archeopyle developed), width 49 µm, Range of 20 specimens: length 36-62 µm, width 35-58 µm
Remarks:
Frequently specimens appear deformed (Plate 1, Figs. 1, 12; Plate 2, Fig. 6). Occasionally specimens are complete without any clear, visible archeopyle (e.g., Plate 1, Figs. 9, 12; Plate 3, Fig. 2). When preservation is bad, the cyst wall can result scabrate, and microreticulation is difficultly distinguishable.
Arcticacysta backmanii Sangiorgi et al., 2009, p.254–255, pl.1, figs.1–12, pl.2, figs.1–9, pl.3, figs.1–2. Holotype: Sangiorgi et al., 2009, pl.1, figs.1–3. Age: ?Early Miocene.
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Original description: [Sangiorgi et al., 2009]:
Diagnosis:
a species of Arcticacysta with a wall ornamented with very low ridges (less than 0.2 µm) which connect to form a microreticulum (details in Plate 1, Fig. 6 and Plate 2, Fig. 9).
The archeopyle, when developed, is of type 3A3I (Plate 1, Figs. 1-5; Plate 2, Figs. 1-5), resulting from the loss of three apical (2’-4’) and three intercalaries (1a-3a).
The sulcus and the cingulum are not indicated, although orientation to the ventral surface is provided by the first apical plate, when clearly visible (Plate 1, Figs. 1-5, Figs 7-8; Plate 2, Figs. 1-5).
Dimensions:
Holotype length 59 µm (archeopyle developed), width 49 µm, Range of 20 specimens: length 36-62 µm, width 35-58 µm
Remarks:
Frequently specimens appear deformed (Plate 1, Figs. 1, 12; Plate 2, Fig. 6). Occasionally specimens are complete without any clear, visible archeopyle (e.g., Plate 1, Figs. 9, 12; Plate 3, Fig. 2). When preservation is bad, the cyst wall can result scabrate, and microreticulation is difficultly distinguishable.