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Wetzeliella coronata
Wetzeliella coronata (Vozzhennikova, 1967) Lentin and Williams, 1976
Originally Rhombodinium, subsequently Wetzeliella, thirdly (and now) Dracodinium.
Taxonomic senior synonym: Wetzeliella articulata, according to Costa and Downie (1979, p.430); however, Iakovleva and Heilmann-Clausen (2010, p. 211,226) retained Rhombodinium (as Wetzeliella) coronatum.
Holotype: Vozzhennikova, 1967, pl.90, fig.4; Lentin and Vozzhennikova, 1990, text-fig.43 (lost, according to Lentin and Vozzhennikova, 1990)
Lectotype: none available, according to Lentin and Vozzhennikova, 1990
Neotype: Iakovleva & Heilmann-Clausen, 2010
Locus typicus: W Siberia (R. Ases-Egan), Russia
Stratum typicum: Late Eocene
Translation Vozzhennikova, 1967: Lentin and Vozzhennikova, 1990
Original description: Vozzhennikova, 1967, p.170-171: Rhombodinium coronatum
Theca pentagonal with well developed horns. Apical horn slightly attenuated, conical, broad or narrow sometimes tapering at the base. Lateral horns truncated at the end, with a clearly discernible transverse furrow. Antapical horns triangular, acutely pointed. Internal body large, oval or oval pentagonal, with a granular surface. Theca large, colored, richly provided with outgrowths of various shapes and sizes, simple, branched or bifurcate at the distal end. Similar outgrowths surround the transverse furrow, the lateral horns and occur on the sides of the theca and the antapical and apical horns. In this way the theca is richly ornamented. The outgrowths occur less frequently on the dorsal and ventral surfaces where they are irregularly distributed. Pylome circular to trapeziform or horseshoe-shaped.
Size: Length 146 µm, width 121.5 µm; length of endocyst 92 µm, width 84 µm. Range, length 108-160 µm, width 105-145 µm; length of endocyst 72-118 µm, width 81-102 µm.
Iakovleva and Heilmannn-Clausen, 2010
Neotype. Plate 12, fig. 4; Slide 473.4-1, England Finder coordinates M44/3; MGUH 29086.
Remarks. The holotype of Wetzeliella coronata is lost according to Lentin and Vozzhennikova (1990). The present material originates from the same region as the type material and includes specimens of Wetzeliella coronata very similar to those illustrated in Vozzhennikova (1967). We therefore designate as a neotype the specimen illustrated in Plate 12, figure 4 which is morphologically close to the lost holotype. We do not agree with Costa and Downie (1979), who considered Wetzeliella coronata to be a junior synonym of Wetzeliella articulata. Wetzeliella coronata differs by its apical horn which is conical, slightly attenuated, sometimes tapering at the base, giving the impression of a crown. Furthermore, the periphragm of Wetzeliella coronata is ornamented by outgrowths of various size and shape, which may be simple, branched or bifurcate at the distal end. The outgrowths border the cingulum, lateral parts of the periphragm, and the horns. The outgrowths (processes) are sparsely and irregularly distributed on the dorsal and ventral surfaces and are often almost absent (Vozzhennikova, 1967, pl. XC, figs. 1–5; Iakovleva et al. 2000, pl. 2, fig. 5; Iakovleva & Kulkova, 2001, pl. 6, figs. 1–4, pl. 10, figs. 1, 4, 8). In contrast to Wetzeliella coronata, Wetzeliella articulata has a short apical horn and its periphragm is covered by evenly distributed, short spine-like bifurcate processes.
Originally Rhombodinium, subsequently Wetzeliella, thirdly (and now) Dracodinium.
Taxonomic senior synonym: Wetzeliella articulata, according to Costa and Downie (1979, p.430); however, Iakovleva and Heilmann-Clausen (2010, p. 211,226) retained Rhombodinium (as Wetzeliella) coronatum.
Holotype: Vozzhennikova, 1967, pl.90, fig.4; Lentin and Vozzhennikova, 1990, text-fig.43 (lost, according to Lentin and Vozzhennikova, 1990)
Lectotype: none available, according to Lentin and Vozzhennikova, 1990
Neotype: Iakovleva & Heilmann-Clausen, 2010
Locus typicus: W Siberia (R. Ases-Egan), Russia
Stratum typicum: Late Eocene
Translation Vozzhennikova, 1967: Lentin and Vozzhennikova, 1990
Original description: Vozzhennikova, 1967, p.170-171: Rhombodinium coronatum
Theca pentagonal with well developed horns. Apical horn slightly attenuated, conical, broad or narrow sometimes tapering at the base. Lateral horns truncated at the end, with a clearly discernible transverse furrow. Antapical horns triangular, acutely pointed. Internal body large, oval or oval pentagonal, with a granular surface. Theca large, colored, richly provided with outgrowths of various shapes and sizes, simple, branched or bifurcate at the distal end. Similar outgrowths surround the transverse furrow, the lateral horns and occur on the sides of the theca and the antapical and apical horns. In this way the theca is richly ornamented. The outgrowths occur less frequently on the dorsal and ventral surfaces where they are irregularly distributed. Pylome circular to trapeziform or horseshoe-shaped.
Size: Length 146 µm, width 121.5 µm; length of endocyst 92 µm, width 84 µm. Range, length 108-160 µm, width 105-145 µm; length of endocyst 72-118 µm, width 81-102 µm.
Iakovleva and Heilmannn-Clausen, 2010
Neotype. Plate 12, fig. 4; Slide 473.4-1, England Finder coordinates M44/3; MGUH 29086.
Remarks. The holotype of Wetzeliella coronata is lost according to Lentin and Vozzhennikova (1990). The present material originates from the same region as the type material and includes specimens of Wetzeliella coronata very similar to those illustrated in Vozzhennikova (1967). We therefore designate as a neotype the specimen illustrated in Plate 12, figure 4 which is morphologically close to the lost holotype. We do not agree with Costa and Downie (1979), who considered Wetzeliella coronata to be a junior synonym of Wetzeliella articulata. Wetzeliella coronata differs by its apical horn which is conical, slightly attenuated, sometimes tapering at the base, giving the impression of a crown. Furthermore, the periphragm of Wetzeliella coronata is ornamented by outgrowths of various size and shape, which may be simple, branched or bifurcate at the distal end. The outgrowths border the cingulum, lateral parts of the periphragm, and the horns. The outgrowths (processes) are sparsely and irregularly distributed on the dorsal and ventral surfaces and are often almost absent (Vozzhennikova, 1967, pl. XC, figs. 1–5; Iakovleva et al. 2000, pl. 2, fig. 5; Iakovleva & Kulkova, 2001, pl. 6, figs. 1–4, pl. 10, figs. 1, 4, 8). In contrast to Wetzeliella coronata, Wetzeliella articulata has a short apical horn and its periphragm is covered by evenly distributed, short spine-like bifurcate processes.