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Palaeoperidinium granulatum
From Fensome et al., 2019:
Palaeoperidinium ?granulatum (Oleinik, 1975, p.225–226, pl.1, figs.3–5) Lentin and Williams, 1981, p.210. Holotype: Oleinik, 1975, pl.1, figs.3–5. Originally Pentagonum granulatum (generic name illegitimate), subsequently (and now) Palaeoperidinium granulatum Oleinik, thirdly Palaeoperidinium oleinikii (name illegitimate). Nomenclatural junior synonym: Palaeoperidinium oleinikii, which has the same type. Questionable assignment: Evitt et al. (1998, p.48). Lentin and Williams (1981, p.210; 1993, p.480) considered this name to be illegitimate, as a junior homonym of Palaeoperidinium granulatum Singh, 1964. However, Williams et al. (1998, p.456) considered the name Palaeoperidinium granulatum Singh to be not validly published, and hence that Palaeoperidinium granulatum Oleinik must be considered a validly published and legitimate name. Age: Late Eocene.
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Plate 1, Fig 3-5
Name of species from granulatum, Lat. - granular.
Holotype: ТО VNIGNI, prep. 364/237-I South Tadzhik depression, Chigim, U. Eocene, lsfarinian-Кhanabadian beds.
Description: Theca pentagonal with three horn-like processes. Epitheca equal to hypotheca or somewhat larger, with small apical horn, pointed or bluntly rounded on distal end. Hypotheca trapezoidal with two small antapical horns. Transverse groove equatorial, rather wide, its margin
bounded by а narrow rim. Longitudinal groove located on hypotheca and often displaced toward its left side. Theca has thin wall, its surface coarse-to-fine-grained. Pilum not observed.
Dimensions: Holotype: length of theca 68.4, width 46.5, length of apical horn 4.9, length of antapical horns 6.3 and 8.4, width of transverse groove 3.7. Other specimens: length of theca 50.7-66.3, width 34.2-48.1, length of apical horns 5.8-10.5 and 6.3-15, width of transverse groove 4.9-6.4, width of rim 2.8.
Comparison: Differs from other species of the genus by its smaller dimensions, fine grained surface of theca and absence of rim on lateral sides of theca.
Geological and Geographical Distribution: U. Eocene, Tadzhikistan.
Collection: Small number of specimens, well and satisfactorily preserved; from South Tadzhik depression (Chigim section and well no. 123 Yalgyz-Kak).
Palaeoperidinium ?granulatum (Oleinik, 1975, p.225–226, pl.1, figs.3–5) Lentin and Williams, 1981, p.210. Holotype: Oleinik, 1975, pl.1, figs.3–5. Originally Pentagonum granulatum (generic name illegitimate), subsequently (and now) Palaeoperidinium granulatum Oleinik, thirdly Palaeoperidinium oleinikii (name illegitimate). Nomenclatural junior synonym: Palaeoperidinium oleinikii, which has the same type. Questionable assignment: Evitt et al. (1998, p.48). Lentin and Williams (1981, p.210; 1993, p.480) considered this name to be illegitimate, as a junior homonym of Palaeoperidinium granulatum Singh, 1964. However, Williams et al. (1998, p.456) considered the name Palaeoperidinium granulatum Singh to be not validly published, and hence that Palaeoperidinium granulatum Oleinik must be considered a validly published and legitimate name. Age: Late Eocene.
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Plate 1, Fig 3-5
Name of species from granulatum, Lat. - granular.
Holotype: ТО VNIGNI, prep. 364/237-I South Tadzhik depression, Chigim, U. Eocene, lsfarinian-Кhanabadian beds.
Description: Theca pentagonal with three horn-like processes. Epitheca equal to hypotheca or somewhat larger, with small apical horn, pointed or bluntly rounded on distal end. Hypotheca trapezoidal with two small antapical horns. Transverse groove equatorial, rather wide, its margin
bounded by а narrow rim. Longitudinal groove located on hypotheca and often displaced toward its left side. Theca has thin wall, its surface coarse-to-fine-grained. Pilum not observed.
Dimensions: Holotype: length of theca 68.4, width 46.5, length of apical horn 4.9, length of antapical horns 6.3 and 8.4, width of transverse groove 3.7. Other specimens: length of theca 50.7-66.3, width 34.2-48.1, length of apical horns 5.8-10.5 and 6.3-15, width of transverse groove 4.9-6.4, width of rim 2.8.
Comparison: Differs from other species of the genus by its smaller dimensions, fine grained surface of theca and absence of rim on lateral sides of theca.
Geological and Geographical Distribution: U. Eocene, Tadzhikistan.
Collection: Small number of specimens, well and satisfactorily preserved; from South Tadzhik depression (Chigim section and well no. 123 Yalgyz-Kak).