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Palaeocystodinium akhmetievi
Palaeocystodinium akhmetievi Vasilyeva in Andreeva-Grigorovich et al., 2011, p.48–49, pl.6, figs. 5–6.
Holotype: Andreeva-Grigorovich et al., 2011, pl.6, figs.5–6.
Age: Danian–Selandian.
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Originals description: [Andreeva-Grigorovich et al., 2011] (translated from Russian):
Palaeocystodinium akhmetievi Vassilyeva sp. nov. Table VI, 5, 6
Name. In honor of the famous geologist and paleobotanist Professor Mikhail Alekseevich Akhmetyev.
Diagnosis. Elongated ellipsoidal proximal or conditionally cornucopia (?) cyst of large size. Well-defined apical and antapical horns. Antapical horn bifurcates, Archaeopile intercalary, elongated, index <0.5. Paracingulum poorly defined.
Description: Pericyst is elongated-ellipsoidal in shape.
with significantly elongated apical and antapical horns. The epicyst is equal in length to the hypocyst. The length of the apical and antapical horns does not exceed half the length of the endocyst. The apical horn is closed, ending in three spines. The distal end of the apical horn is ornamented with tiny spines. The antapical horn bifurcates, resembling a united pair of antapical horns. The endocyst is elongated-ellipsoidal, pointed at the poles, closely adjoining the pericyst. The pericoel is practically absent or insignificant at the poles. The periphragm is thin, folded. Shallow folds are oriented meridionally. Denser strands extend towards the poles. The endophragm is thin, possibly finely punctate, closely adjoining the periphragm. The paracingulum is practically not expressed, sometimes marked by thin transverse folds of the periphragm. The presence of a small epicoel and hypocoel, limited by the space at the base of the horns, is possible. However, this space is almost not visible. The periarcheopyle is intercalary, vertically elongated, trapezoid in shape. The perioperculum is attached. The paratabulation is expressed by the archeopyle and a slightly marked paracingulum.
Holotype. Plate VI, 5, 6. Prep. LD-1-52, collection of the Institute of Geology and Mineralogy, Ural Branch of the Russian Academy of Sciences.
Locality. Section of borehole LD-1 Lipovskaya, Tura River, Talitskaya suite (Sverdlovsk region, Lipovskoye settlement).
Dimensions (µm). Holotype: pericyst length 165; pericyst width 33; endocyst length 92.4; endocyst width - 33; apical horn length 33; antapical horn length - 39.6; length of its bifurcated ends - 23. Other specimens (5 specimens): pericyst length 191-163, endocyst 102.0-79.2; apical horn 39.6.
Comparison: Differs significantly from other species of Palaeocystodiniur in the structure of the antapical horn and the proportions of the endocyst and horns.
Notes. The morphotype is stable and easy to diagnose. It occurs stably, in small quantities.
Distribution. Russia, Middle Trans-Urals, Talitskaya suite (Upper Talitskaya subsuite). Paleocene (Danian-Selandian).
Holotype: Andreeva-Grigorovich et al., 2011, pl.6, figs.5–6.
Age: Danian–Selandian.
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Originals description: [Andreeva-Grigorovich et al., 2011] (translated from Russian):
Palaeocystodinium akhmetievi Vassilyeva sp. nov. Table VI, 5, 6
Name. In honor of the famous geologist and paleobotanist Professor Mikhail Alekseevich Akhmetyev.
Diagnosis. Elongated ellipsoidal proximal or conditionally cornucopia (?) cyst of large size. Well-defined apical and antapical horns. Antapical horn bifurcates, Archaeopile intercalary, elongated, index <0.5. Paracingulum poorly defined.
Description: Pericyst is elongated-ellipsoidal in shape.
with significantly elongated apical and antapical horns. The epicyst is equal in length to the hypocyst. The length of the apical and antapical horns does not exceed half the length of the endocyst. The apical horn is closed, ending in three spines. The distal end of the apical horn is ornamented with tiny spines. The antapical horn bifurcates, resembling a united pair of antapical horns. The endocyst is elongated-ellipsoidal, pointed at the poles, closely adjoining the pericyst. The pericoel is practically absent or insignificant at the poles. The periphragm is thin, folded. Shallow folds are oriented meridionally. Denser strands extend towards the poles. The endophragm is thin, possibly finely punctate, closely adjoining the periphragm. The paracingulum is practically not expressed, sometimes marked by thin transverse folds of the periphragm. The presence of a small epicoel and hypocoel, limited by the space at the base of the horns, is possible. However, this space is almost not visible. The periarcheopyle is intercalary, vertically elongated, trapezoid in shape. The perioperculum is attached. The paratabulation is expressed by the archeopyle and a slightly marked paracingulum.
Holotype. Plate VI, 5, 6. Prep. LD-1-52, collection of the Institute of Geology and Mineralogy, Ural Branch of the Russian Academy of Sciences.
Locality. Section of borehole LD-1 Lipovskaya, Tura River, Talitskaya suite (Sverdlovsk region, Lipovskoye settlement).
Dimensions (µm). Holotype: pericyst length 165; pericyst width 33; endocyst length 92.4; endocyst width - 33; apical horn length 33; antapical horn length - 39.6; length of its bifurcated ends - 23. Other specimens (5 specimens): pericyst length 191-163, endocyst 102.0-79.2; apical horn 39.6.
Comparison: Differs significantly from other species of Palaeocystodiniur in the structure of the antapical horn and the proportions of the endocyst and horns.
Notes. The morphotype is stable and easy to diagnose. It occurs stably, in small quantities.
Distribution. Russia, Middle Trans-Urals, Talitskaya suite (Upper Talitskaya subsuite). Paleocene (Danian-Selandian).