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Ceratiopsis boloniensis
Ceratiopsis boloniensis, (Riegel, 1974), Lentin and Williams, 1977
Combination illegitimate since the generic name Ceratiopsis is illegitimate.
Now Cerodinium. Originally Deflandrea, subsequently Ceratiopsis (combination illegitimate), thirdly Senegalinium, fourthly Phelodinium, fifthly (and now) Cerodinium.
Holotype: Riegel, 1974, pl.1, fig.7
Locus typicus: Puerto de Bolonia, Province of Cadiz, Spain
Stratum typicum: Senonian?
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Original description as Deflandrea boloniensis: [Riegel, 1974, p.354-356]:
Diagnosis:
Large species of Deflandrea. Outline of body pentagonal with straight sides and well developed apical and equal antapical horns. Capsule closely adhering to sides and base of outer wall, but not extending into horns. Girdle conspicuous by low ledges and folds in outer wall, sulcus bordered by longitudinal folds bearing flagellar pocket on its left side.
Intercalary archeopyle large, six-sided with alternating long and short sides. Surface showing irregular longitudinal striations.
Description:
The straight sides of the body and the resulting pentagonal outline are a consisted characteristic of this species except for a few unusually small specimens having slightly convex sides. The general lack of larger compression folds indicates that the cysts were flattened dorso-ventrally prior to compression.
The apical horn is a slightly tapering to nearly parallel-sided extension of the outer wall with a broadly flaring base measuring about 2/5 of the length of the body. In the majority of specimens its extreme tip is bent over or indented thus appearing slightly blunted. Only the largest specimens have a fully inflated and pointed tip. The antapical horns are more or less equal in size, somewhat shorter than the apical horn and steeply pyramidal, terminating in an acute point. The distance between them equals or slightly exceeds the width of the horns at base.
The conspicuous girdle is weakly helicoidal, but sinuous, crossing the body about midway. It consists of a narrow groove about 5 µm in width bordered on either side by a fine, frilled ledge and simple continuous folds.
The sulcus is considerably broader, open at both ends and bordered laterally by minor folds. Slightly below the juncture of the girdle and the left bordering fold a dark semicircular area projecting into the sulcus is formed by a pocket-like invagination of the wall corresponding to flagellar markings observed by other authors.
The capsule normally fills the body completely, nut never extends into the horns. In a few exceptionally small forms the capsule is smaller than the body and more rounded. Along the sides of the body the capsule wall appears to be fused to the outer wall. Opposite the horns the capsule wall is frequently somewhat thickened or covered with tubercles.
The intercalary archeopyle, involving outer as well as capsule wall, is unusually large extending from the base of the apical horn almost to the girdle and leaving only a narrow strip in the position of plate 3""". It is shaped like a triangle with truncated corners, its posterior side being about double the length of the anterior side. Smaller cysts show incomplete or no archeopyle development.
The irregular longitudinal striations on the shell surface are formed by fine wrinkles in the outer wall. Near the girdle they tend to be wavy and arranged at more regular intervals. In some well preserved specimens single rows of pores have been observed between them. The thickness of the capsule wall rarely exceeds 1 µm, the outer wall is considerably thinner. Both walls, particularly the capsule wall. have a distinctive brown colour.
Dimensions:
Size: Total length 144 µm, body length 84 µm, width 93 µm.
Range of length including horns: 78-156 µm; mean: 113.8 µm; standard deviation: 17.5. Range of capsule length: 35-87 µm; mean: 70.1 µm. Range of width: 50-99 µm; mean: 76.8 µm: standard deviation: 11.7. 52 specimens measured.
Affinities:
Great size and equal antapical horns as exhibited by D. boloniensis are unusual among Cretaceous species of Deflandrea.
D. boloniensis resembles D. magnifica Stanley 1965 and D. pannucea Stanley 1965 both from the Paleocene Fort Union formation of South Dakota, U. S. A., by its pentagonal outline and longitudinal striations. D. magnifica, however, has shorter and broader horns and is occasionally covered with spines, whereas D. pannucea differs in archeopyle shape and in having proportionately longer antapical horns. Both species appear distinctly lighter in colour and flagellar markings have not been mentioned for either of them. D. striata Drugg 1967 differs in shape and nature of striations (rows of grana). Cerodinium sibiricum Vozzhenikova 1963 is somewhat similar with regard to shape, surficial striations and girdle border, but appears to lack an archeopyle and flagellar pocket.
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Emended diagnosis as Phelodinium boloniensis:
Riegel and Sarjeant, 1982, p.297:
Diagnosis:
Cyst cornucavate, the apical cavation extending beyond the horn base so that (save for the presence of antapical horns) the epicavate condition is approached. Ambitus of central body roughly hexagonal; epitract in the form of a truncated cone, hypotract more rounded.
Apical and antapical horns well developed and of closely similar length: apical horn typically blunt tipped, antapical horns with pointed tips.
Paracingulum defined by low crests and folds; parasulcus marked by longitudinal folds, with a flagellar pocket on its left median flank.
The periphragm surface exhibits irregular longitudinal striations.
Intercalary archaeopyle of standard hexa type, developed by loss of paraplate 2a; it is very large, extending almost to the paracingulum and penetrating both wall layers (type I/I); the epipericoel opens to the exterior through the anterior section of the archaeopyle. The operculum may be free or may retain some degree of antapical attachment.
Combination illegitimate since the generic name Ceratiopsis is illegitimate.
Now Cerodinium. Originally Deflandrea, subsequently Ceratiopsis (combination illegitimate), thirdly Senegalinium, fourthly Phelodinium, fifthly (and now) Cerodinium.
Holotype: Riegel, 1974, pl.1, fig.7
Locus typicus: Puerto de Bolonia, Province of Cadiz, Spain
Stratum typicum: Senonian?
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description as Deflandrea boloniensis: [Riegel, 1974, p.354-356]:
Diagnosis:
Large species of Deflandrea. Outline of body pentagonal with straight sides and well developed apical and equal antapical horns. Capsule closely adhering to sides and base of outer wall, but not extending into horns. Girdle conspicuous by low ledges and folds in outer wall, sulcus bordered by longitudinal folds bearing flagellar pocket on its left side.
Intercalary archeopyle large, six-sided with alternating long and short sides. Surface showing irregular longitudinal striations.
Description:
The straight sides of the body and the resulting pentagonal outline are a consisted characteristic of this species except for a few unusually small specimens having slightly convex sides. The general lack of larger compression folds indicates that the cysts were flattened dorso-ventrally prior to compression.
The apical horn is a slightly tapering to nearly parallel-sided extension of the outer wall with a broadly flaring base measuring about 2/5 of the length of the body. In the majority of specimens its extreme tip is bent over or indented thus appearing slightly blunted. Only the largest specimens have a fully inflated and pointed tip. The antapical horns are more or less equal in size, somewhat shorter than the apical horn and steeply pyramidal, terminating in an acute point. The distance between them equals or slightly exceeds the width of the horns at base.
The conspicuous girdle is weakly helicoidal, but sinuous, crossing the body about midway. It consists of a narrow groove about 5 µm in width bordered on either side by a fine, frilled ledge and simple continuous folds.
The sulcus is considerably broader, open at both ends and bordered laterally by minor folds. Slightly below the juncture of the girdle and the left bordering fold a dark semicircular area projecting into the sulcus is formed by a pocket-like invagination of the wall corresponding to flagellar markings observed by other authors.
The capsule normally fills the body completely, nut never extends into the horns. In a few exceptionally small forms the capsule is smaller than the body and more rounded. Along the sides of the body the capsule wall appears to be fused to the outer wall. Opposite the horns the capsule wall is frequently somewhat thickened or covered with tubercles.
The intercalary archeopyle, involving outer as well as capsule wall, is unusually large extending from the base of the apical horn almost to the girdle and leaving only a narrow strip in the position of plate 3""". It is shaped like a triangle with truncated corners, its posterior side being about double the length of the anterior side. Smaller cysts show incomplete or no archeopyle development.
The irregular longitudinal striations on the shell surface are formed by fine wrinkles in the outer wall. Near the girdle they tend to be wavy and arranged at more regular intervals. In some well preserved specimens single rows of pores have been observed between them. The thickness of the capsule wall rarely exceeds 1 µm, the outer wall is considerably thinner. Both walls, particularly the capsule wall. have a distinctive brown colour.
Dimensions:
Size: Total length 144 µm, body length 84 µm, width 93 µm.
Range of length including horns: 78-156 µm; mean: 113.8 µm; standard deviation: 17.5. Range of capsule length: 35-87 µm; mean: 70.1 µm. Range of width: 50-99 µm; mean: 76.8 µm: standard deviation: 11.7. 52 specimens measured.
Affinities:
Great size and equal antapical horns as exhibited by D. boloniensis are unusual among Cretaceous species of Deflandrea.
D. boloniensis resembles D. magnifica Stanley 1965 and D. pannucea Stanley 1965 both from the Paleocene Fort Union formation of South Dakota, U. S. A., by its pentagonal outline and longitudinal striations. D. magnifica, however, has shorter and broader horns and is occasionally covered with spines, whereas D. pannucea differs in archeopyle shape and in having proportionately longer antapical horns. Both species appear distinctly lighter in colour and flagellar markings have not been mentioned for either of them. D. striata Drugg 1967 differs in shape and nature of striations (rows of grana). Cerodinium sibiricum Vozzhenikova 1963 is somewhat similar with regard to shape, surficial striations and girdle border, but appears to lack an archeopyle and flagellar pocket.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Emended diagnosis as Phelodinium boloniensis:
Riegel and Sarjeant, 1982, p.297:
Diagnosis:
Cyst cornucavate, the apical cavation extending beyond the horn base so that (save for the presence of antapical horns) the epicavate condition is approached. Ambitus of central body roughly hexagonal; epitract in the form of a truncated cone, hypotract more rounded.
Apical and antapical horns well developed and of closely similar length: apical horn typically blunt tipped, antapical horns with pointed tips.
Paracingulum defined by low crests and folds; parasulcus marked by longitudinal folds, with a flagellar pocket on its left median flank.
The periphragm surface exhibits irregular longitudinal striations.
Intercalary archaeopyle of standard hexa type, developed by loss of paraplate 2a; it is very large, extending almost to the paracingulum and penetrating both wall layers (type I/I); the epipericoel opens to the exterior through the anterior section of the archaeopyle. The operculum may be free or may retain some degree of antapical attachment.