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Apteodinium daveyi
From Fensome et al., 2019:
Apteodinium daveyi Poulsen, 1996, p.70–71, pl.13, figs.1–4. Holotype: Poulsen, 1996, pl.13, figs.1–3. Age: latest Jurassic–earliest Cretaceous.
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Original description:
Diagnosis:
A smooth, proximate, ovoidal to subrhomboidal cyst with a small apical projection. The autophragm is smooth, spongy (vesicular) and thick (up to 7 µm).
The paratabulation is indicated only by the cingulum and the large archeopyle. However, in interference contrast weak indications of a gonyaulacoid paratabulation may be visible.
The archeopyle is precingular, type P3"", operculum free.
The parasulcus is elongate.
Description:
An ovoidal to subrhomboidal species of Apteodinium with a small blunt apical horn.
The autophragm is thick (up to 7 µm) and spongy.
The paratabulation is typically indicated only by archeopyle and paracingulum, the latter being about 5 µm in width and marked by weak parallel ridges.
The archeopyle is precingular (type P3"") and long, extending almost to the apex. The archeopyle may be enlarged, overlapping onto part the of apical paraplate series. The size of the cyst is intermediate.
Dimensions:
9 specimens measured. Length of horn 6-8 µm, paracingulum width 5 µm, wall thickness 4-7 µm.
Holotype: length 87 µm, width 63 µm.
Overall cyst length (minimum-mean-maximum): 68 µm - 85 µm - 103 µm.
Overall cyst width (minimum-mean-maximum): 56 µm - 65 µm- 76 µm.
Affinities/Comparison:
Apteodinium daveyi is separated from other Apteodinium species with a spongy wall by the size of the horn, the smooth surface and an intraperforate wall structure, as opposed to a spongy-fibrous structure.
Apteodinium daveyi Poulsen, 1996, p.70–71, pl.13, figs.1–4. Holotype: Poulsen, 1996, pl.13, figs.1–3. Age: latest Jurassic–earliest Cretaceous.
---------------------------------------------------------------------------------------------------
Original description:
Diagnosis:
A smooth, proximate, ovoidal to subrhomboidal cyst with a small apical projection. The autophragm is smooth, spongy (vesicular) and thick (up to 7 µm).
The paratabulation is indicated only by the cingulum and the large archeopyle. However, in interference contrast weak indications of a gonyaulacoid paratabulation may be visible.
The archeopyle is precingular, type P3"", operculum free.
The parasulcus is elongate.
Description:
An ovoidal to subrhomboidal species of Apteodinium with a small blunt apical horn.
The autophragm is thick (up to 7 µm) and spongy.
The paratabulation is typically indicated only by archeopyle and paracingulum, the latter being about 5 µm in width and marked by weak parallel ridges.
The archeopyle is precingular (type P3"") and long, extending almost to the apex. The archeopyle may be enlarged, overlapping onto part the of apical paraplate series. The size of the cyst is intermediate.
Dimensions:
9 specimens measured. Length of horn 6-8 µm, paracingulum width 5 µm, wall thickness 4-7 µm.
Holotype: length 87 µm, width 63 µm.
Overall cyst length (minimum-mean-maximum): 68 µm - 85 µm - 103 µm.
Overall cyst width (minimum-mean-maximum): 56 µm - 65 µm- 76 µm.
Affinities/Comparison:
Apteodinium daveyi is separated from other Apteodinium species with a spongy wall by the size of the horn, the smooth surface and an intraperforate wall structure, as opposed to a spongy-fibrous structure.