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Hystrichosphaeridium articulatum
Hystrichosphaeridium articulatum (Eisenack, 1938) Pastiels, 1948
NOW Wetzeliella. Originally (and now) Wetzeliella, subsequently Palaeoperidinium (name not validly published), thirdly Hystrichosphaeridium, fourthly Wetzeliella subgenus Wetzeliella.
Taxonomic junior synonyms: Wetzeliella echinulata, according to Costa and Downie (1979, p.40); Wetzeliella horrida, according to Stover and Evitt (1978, p.131); Rhombodinium (as Wetzeliella) coronatum, according to Costa and Downie (1979, p.43) — however, Iakovleva and Heilmann-Clausen (2010, p. 211,226) retained Rhombodinium (as Wetzeliella) coronatum; Rhombodinium pentagonum, according to Costa and Downie (1979, p.40) — however, Lentin and Williams (1981, p.244) retained Rhombodinium pentagonum; Wetzeliella hampdenensis, according to Costa and Downie (1979, p.40) — however, Lentin and Williams (1981, p.290) retained Wetzeliella hampdenensis; Wetzeliella (now Charlesdowniea) clathrata, according to Pastiels (1948, p.42) — however, this synonymy has not been generally accepted.
Holotype: Eisenack, 1938b, fig.4; Eisenack, 1954b, pl.7, fig.3 (not pl.7, fig.1 as indicated in Eisenack, 1954b, p.90)
Age: Late Eocene-Early Oligocene
Eisenack, 1938, p. 186-187
(annotated) Amongst the dinoflagellates, which form a remarkable portion of the small forms of the phosphorites, two groups are discerned: In the first we encounter forms, which do not essentially differ from the Recent species and which are easily classified in the known genera; in the other group there are species, which apparently belong in the tertiary , and which have not yet been encountered in the Cretaceous. They are principally three species with firm membranes: Wetzeliella articulata (O. Wetzel), Wetzeliella clathrata and Deflandrea phosphoritica. O. Wetzel initially classified the first species as Palaeoperidinium articulatum. Wetzeliella clathrata differs from it in the more diamond-shaped outline and the balustrade-like fusion of the marginal spines. Nevertheless, in my opinion these two species are not related to Palaeoperidinium because of the absence of tabulation or signs thereof, and because of the character of the furrows. Therefore I would suggest the name Wetzeliella to accomodate both species.
Original description: Eisenack 1954, p. 55
Diagnosis: Central body is flattened, the shape in outline is rhomboidal, with an apical horn, two lateral horns, and two mainly unequal antapical horns, which gives the total outline a characteristic peridinioid-like pentagonal shape. The shell is untabulated, thick, and transparant. The transverse furrow is sometimes indicated (?), the longitudinal furrow is not developed. The shell, especially the sharp margins, is provided with short, strong thorns (or brushes). Inside, a circular to ellipsoidal, similarly flattened inner capsule is present, which does not touch the outer wall.
Description (annotated): W.articulata varies heavily. The apical horn is nearly always distinct, the lateral horns extend unequally far, which affects the length-width. Generally also the antapical horns are clearly developed and unequal in size; the difference between them can be obscure, but also extensive. The apical and antapical horns are always sharp; the lateral horns are rounded or indented, which is often expressed by the diverging marginal spines. The shell in untabulated, transparent, brownish, yellowish to almost colourless. The (more or less closely spaced) ornamentation of brushes does not show a distinct arrangment. The ends of the brushes are often slightly furcate.
In the type-specimen dorsally, where the transversal furrow is to be expected, a crack 'yawns' from the right lateral horn up to almost the left horn; the bordering thorns at the margins of the crack are slightly curved, which produces a more distinct line. The ovoidal to circular inner capsule leaves between itself and the outer wall of the shell a more or less broad belt. Between shell and capsule a cavity is present; the apical horn, lateral horns, and antapical horns are cavate. Only at the dorsal and ventral sides both bodies touch each other.
Dimensions: Length: 114-196 µm; width: 105-178 µm; Generally the length/width ratio is sligthly larger than 1.
Gocht, 1969, p.13:
Only very few specimens represented this species, which was common in the Eocene. Three are well preserved and characteristic. Among the Wetzeliella specimens of uncertain identification, there are also some which could be classed in the vicinity of W. articulata, but could also fall within the range of variation of other species. These specimens are mostly very fragile.
The archeopyle, which is not very large, is rounded-trapezoidal to oval. The archeopyle margins of capsule and outer membrane are congruent, as could be observed also on specimens from the Eocene of Heiligenhafen (material of Agelopoulos). One of the typical individuals exhibits a splendid flagellar inesertion.
Material: 4 specimens.
Occurrence: ?Late Eocene- Middle Oligocene.
NOW Wetzeliella. Originally (and now) Wetzeliella, subsequently Palaeoperidinium (name not validly published), thirdly Hystrichosphaeridium, fourthly Wetzeliella subgenus Wetzeliella.
Taxonomic junior synonyms: Wetzeliella echinulata, according to Costa and Downie (1979, p.40); Wetzeliella horrida, according to Stover and Evitt (1978, p.131); Rhombodinium (as Wetzeliella) coronatum, according to Costa and Downie (1979, p.43) — however, Iakovleva and Heilmann-Clausen (2010, p. 211,226) retained Rhombodinium (as Wetzeliella) coronatum; Rhombodinium pentagonum, according to Costa and Downie (1979, p.40) — however, Lentin and Williams (1981, p.244) retained Rhombodinium pentagonum; Wetzeliella hampdenensis, according to Costa and Downie (1979, p.40) — however, Lentin and Williams (1981, p.290) retained Wetzeliella hampdenensis; Wetzeliella (now Charlesdowniea) clathrata, according to Pastiels (1948, p.42) — however, this synonymy has not been generally accepted.
Holotype: Eisenack, 1938b, fig.4; Eisenack, 1954b, pl.7, fig.3 (not pl.7, fig.1 as indicated in Eisenack, 1954b, p.90)
Age: Late Eocene-Early Oligocene
Eisenack, 1938, p. 186-187
(annotated) Amongst the dinoflagellates, which form a remarkable portion of the small forms of the phosphorites, two groups are discerned: In the first we encounter forms, which do not essentially differ from the Recent species and which are easily classified in the known genera; in the other group there are species, which apparently belong in the tertiary , and which have not yet been encountered in the Cretaceous. They are principally three species with firm membranes: Wetzeliella articulata (O. Wetzel), Wetzeliella clathrata and Deflandrea phosphoritica. O. Wetzel initially classified the first species as Palaeoperidinium articulatum. Wetzeliella clathrata differs from it in the more diamond-shaped outline and the balustrade-like fusion of the marginal spines. Nevertheless, in my opinion these two species are not related to Palaeoperidinium because of the absence of tabulation or signs thereof, and because of the character of the furrows. Therefore I would suggest the name Wetzeliella to accomodate both species.
Original description: Eisenack 1954, p. 55
Diagnosis: Central body is flattened, the shape in outline is rhomboidal, with an apical horn, two lateral horns, and two mainly unequal antapical horns, which gives the total outline a characteristic peridinioid-like pentagonal shape. The shell is untabulated, thick, and transparant. The transverse furrow is sometimes indicated (?), the longitudinal furrow is not developed. The shell, especially the sharp margins, is provided with short, strong thorns (or brushes). Inside, a circular to ellipsoidal, similarly flattened inner capsule is present, which does not touch the outer wall.
Description (annotated): W.articulata varies heavily. The apical horn is nearly always distinct, the lateral horns extend unequally far, which affects the length-width. Generally also the antapical horns are clearly developed and unequal in size; the difference between them can be obscure, but also extensive. The apical and antapical horns are always sharp; the lateral horns are rounded or indented, which is often expressed by the diverging marginal spines. The shell in untabulated, transparent, brownish, yellowish to almost colourless. The (more or less closely spaced) ornamentation of brushes does not show a distinct arrangment. The ends of the brushes are often slightly furcate.
In the type-specimen dorsally, where the transversal furrow is to be expected, a crack 'yawns' from the right lateral horn up to almost the left horn; the bordering thorns at the margins of the crack are slightly curved, which produces a more distinct line. The ovoidal to circular inner capsule leaves between itself and the outer wall of the shell a more or less broad belt. Between shell and capsule a cavity is present; the apical horn, lateral horns, and antapical horns are cavate. Only at the dorsal and ventral sides both bodies touch each other.
Dimensions: Length: 114-196 µm; width: 105-178 µm; Generally the length/width ratio is sligthly larger than 1.
Gocht, 1969, p.13:
Only very few specimens represented this species, which was common in the Eocene. Three are well preserved and characteristic. Among the Wetzeliella specimens of uncertain identification, there are also some which could be classed in the vicinity of W. articulata, but could also fall within the range of variation of other species. These specimens are mostly very fragile.
The archeopyle, which is not very large, is rounded-trapezoidal to oval. The archeopyle margins of capsule and outer membrane are congruent, as could be observed also on specimens from the Eocene of Heiligenhafen (material of Agelopoulos). One of the typical individuals exhibits a splendid flagellar inesertion.
Material: 4 specimens.
Occurrence: ?Late Eocene- Middle Oligocene.