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Laciniadinium
From Williams et al., 2017:
[Laciniadinium, Mclntyre, 1975, p. 70
Type species: Laciniadinium orbiculatum, McIntyre, 1975 (pl.4, figs.12–13)]
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Original description: [McIntyre, 1975]:
Cysts proximate, spherical to rhombic, dorsoventrally flattened. Apical and antapical horns present or absent. Wall single layered except at apex where 2 layers may be present, smooth to granulate to echinate. Cingulum visible as low ridges, sulcus present but indistinct.
Archeopyle may be present, smooth to granular combination type, intercalary-precingular (313Pa); operculum attached at cingulum, simple, flap-like, formed of reflected plates 1a, 2a, 3a, 3``, 4``, 5``.
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Modified description:
Stover and Evitt, 1978, p. 211:
Synopsis:
Cysts proximate, compressed subspherical to nearly biconical, with or without apical and antapical horns; autophragm smooth or ornamented with features of low relief; paratabulation indicated by archeopyle and paracingulum; archeopyle combination, Type tl3Pa.
Description:
Shape: Compressed subspherical to nearly biconical; apical and antapical horns may be present.
Wall relationships: Autophragm only, except at apex, where two layers may be present.
Wall features: No parasutural features. Autophragm has scattered features of low relief.
Paratabulation: Indicated by archeopyle and paracingulum.
Archeopyle: Combination, Type tl3Pa, involves paraplates la to 3a and 3" to 5"; operculum flaplike, simple, and attached antapically along paracingulum.
Paracingulum: Indicated by low transverse parallel ridges, or rows of granules or cones, or combination thereof.
Parasulcus: Generally not indicated.
Size: Intermediate.
Affinities:
Laciniadinium differs from Luxadinium in having an attached rather than a free operculum. It differs from Saeptodinium and Paleoperidinium in that no third apical paraplate is involved in the formation of the archeopyle.
[Laciniadinium, Mclntyre, 1975, p. 70
Type species: Laciniadinium orbiculatum, McIntyre, 1975 (pl.4, figs.12–13)]
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Original description: [McIntyre, 1975]:
Cysts proximate, spherical to rhombic, dorsoventrally flattened. Apical and antapical horns present or absent. Wall single layered except at apex where 2 layers may be present, smooth to granulate to echinate. Cingulum visible as low ridges, sulcus present but indistinct.
Archeopyle may be present, smooth to granular combination type, intercalary-precingular (313Pa); operculum attached at cingulum, simple, flap-like, formed of reflected plates 1a, 2a, 3a, 3``, 4``, 5``.
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Modified description:
Stover and Evitt, 1978, p. 211:
Synopsis:
Cysts proximate, compressed subspherical to nearly biconical, with or without apical and antapical horns; autophragm smooth or ornamented with features of low relief; paratabulation indicated by archeopyle and paracingulum; archeopyle combination, Type tl3Pa.
Description:
Shape: Compressed subspherical to nearly biconical; apical and antapical horns may be present.
Wall relationships: Autophragm only, except at apex, where two layers may be present.
Wall features: No parasutural features. Autophragm has scattered features of low relief.
Paratabulation: Indicated by archeopyle and paracingulum.
Archeopyle: Combination, Type tl3Pa, involves paraplates la to 3a and 3" to 5"; operculum flaplike, simple, and attached antapically along paracingulum.
Paracingulum: Indicated by low transverse parallel ridges, or rows of granules or cones, or combination thereof.
Parasulcus: Generally not indicated.
Size: Intermediate.
Affinities:
Laciniadinium differs from Luxadinium in having an attached rather than a free operculum. It differs from Saeptodinium and Paleoperidinium in that no third apical paraplate is involved in the formation of the archeopyle.