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Charlesdowniea clathrata
Charlesdowniea clathrata, (Eisenack, 1938), Lentin and Vozzhennikova, 1989
Originally Wetzeliella, subsequently Kisselevia?, thirdly Charlesdowniea, fourthly (and now) Talladinium?
Pastiels, 1948, considered this species to be a tax. synonym of Wetzeliella (as Hystrichosphaeridium) articulata Eisenack, 1938. This has not been generally accepted by subsequent authors.
Holotype: Eisenack, 1938b, text-fig.5; Eisenack, 1954, pl.7, fig.12
Locus typicus: Palmnicken, Samland, Russia
Stratum typicum: Late Eocene-Early Oligocene
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Original description as Wetzeliella clathrata: [Eisenack, 1938, p. 187]: (Translation: LP):
Description:
Wetzeliella clathrata differs from Wetzeliella articulata in its stronger diamond shape and the balustrade-like fusion of the marginal spines.
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Supplemental description:
Eisenack, 1954, p. 57: (Translation: LP):
Diagnosis:
Body flattened, outline more strongly diamond-shaped than in W. articulata, because the "horns" project much less, the smaller antapical horn either indicated as a mere bulge of the margin or totally reduced. The horns are arranged in rows and form, by the fusion of their ends, characteristical balustrade- like fences, which are most clearly visible along the sides, but also stand on the front and back sides, there delimiting several fields. The area of the transverse furrow is sometimes delimited quite clearly by such balustrades. Capsule oval, located mostly farther from the margin than in W. articulata. Longitudinal not observable.
Dimensions:
Holotype: 160:150 µm, capsule 83:81 µm. 11 specimens observed, 134-165 µm long.
Affinities: (p. 57-58):
(annotated) W. clathrata differs from W. articulata in the formation of the balustrade-like fences, and from other related species in the general habit. The body is essentially flatter and more strongly diamond-shaped, resulting from the reduction of the horns. A delimitation of fields by rows of thorns is not present in W. articulata, but clearly observable in W. clathrata.
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Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999
Charlesdowniea clathrata (Eisenack, 1938b) Lentin and Vozzhennikova, 1989. According to Eisenack (1954, p. ), this species has processes aligned in rows and united distally with one another, forming a characteristic trellis-like reticulum. The pericyst is rhomboidal and the horns are reduced. Michoux (1988) differentiates Charlesdowniea columna from C.clathrata on the basis of the former having a larger right antapical horn, a less rhombic outline and less convex sides. Also the ectophragm of C.clathrata is developed by fusion of adjacent process tips, not developed into a membrane.
Size: length 134-165 µm, endocyst. Capsule about 82 µm.
Originally Wetzeliella, subsequently Kisselevia?, thirdly Charlesdowniea, fourthly (and now) Talladinium?
Pastiels, 1948, considered this species to be a tax. synonym of Wetzeliella (as Hystrichosphaeridium) articulata Eisenack, 1938. This has not been generally accepted by subsequent authors.
Holotype: Eisenack, 1938b, text-fig.5; Eisenack, 1954, pl.7, fig.12
Locus typicus: Palmnicken, Samland, Russia
Stratum typicum: Late Eocene-Early Oligocene
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description as Wetzeliella clathrata: [Eisenack, 1938, p. 187]: (Translation: LP):
Description:
Wetzeliella clathrata differs from Wetzeliella articulata in its stronger diamond shape and the balustrade-like fusion of the marginal spines.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Supplemental description:
Eisenack, 1954, p. 57: (Translation: LP):
Diagnosis:
Body flattened, outline more strongly diamond-shaped than in W. articulata, because the "horns" project much less, the smaller antapical horn either indicated as a mere bulge of the margin or totally reduced. The horns are arranged in rows and form, by the fusion of their ends, characteristical balustrade- like fences, which are most clearly visible along the sides, but also stand on the front and back sides, there delimiting several fields. The area of the transverse furrow is sometimes delimited quite clearly by such balustrades. Capsule oval, located mostly farther from the margin than in W. articulata. Longitudinal not observable.
Dimensions:
Holotype: 160:150 µm, capsule 83:81 µm. 11 specimens observed, 134-165 µm long.
Affinities: (p. 57-58):
(annotated) W. clathrata differs from W. articulata in the formation of the balustrade-like fences, and from other related species in the general habit. The body is essentially flatter and more strongly diamond-shaped, resulting from the reduction of the horns. A delimitation of fields by rows of thorns is not present in W. articulata, but clearly observable in W. clathrata.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999
Charlesdowniea clathrata (Eisenack, 1938b) Lentin and Vozzhennikova, 1989. According to Eisenack (1954, p. ), this species has processes aligned in rows and united distally with one another, forming a characteristic trellis-like reticulum. The pericyst is rhomboidal and the horns are reduced. Michoux (1988) differentiates Charlesdowniea columna from C.clathrata on the basis of the former having a larger right antapical horn, a less rhombic outline and less convex sides. Also the ectophragm of C.clathrata is developed by fusion of adjacent process tips, not developed into a membrane.
Size: length 134-165 µm, endocyst. Capsule about 82 µm.