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Cerodinium wardenense
Cerodinium wardenense, (Williams and Downie, 1966), Lentin and Williams, 1987
Originally Deflandrea, subsequently (and now) Cerodinium; see also Ceratiopsis (combination illegitimate).
Holotype: Williams and Downie, 1966, pl.26, fig.5, Bujak et al., 1980, pl.11, fig.3
Locus typicus: London Clay, Sheppey, Kent, England
Stratum typicum: Eocene
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Original description as Deflandrea wardenensis: [Williams and Downie, 1966, p. 223]:
Diagnosis:
Cavate cysts, sub-circular to ovoidal periphragm, one apical and two short antapical horns. Conical apical horn merging imperceptibly into lateral walls; two antapical horns more positively delimited and straight or slightly diverging. Length of antapical horns approximately equal. Thin walled ovoidal capsule, closely appressed to periphragm except at horns. Surface of periphragm has short acuminate or blunt processes, not restricted to sutures of cingulum and sulcus. Archaeopyle common.
Description:
The epitract is longer than the hypotract. In outline the former is conical with convex lateral sides, the latter is rounded with the antapical horns being sharply delimited. All three horns can be acuminate but are more commonly blunt. The antapical horns are well separated. The equatorial and longitudinal furrows are both wide with the latter broadening posteriorly. Five postcingulars have been discerned; the rest of the tabulation is too difficult to decipher.
Dimensions:
Holotype: periphragm, length 57 µm, breadth 46 µm; capsule, length 36 µm, breadth 43 µm.
Observed range: periphragm, length 46-64 µm, breadth 43-50 µm, capsule, length 33-41 µm, breadth 40-46 µm.
Affinities:
Species of Deflandrea having processes on the sutures of the cingulum, sulcus and plate boundaries are D. denticulata; D. echinoidea Cookson & Eisenack 1958 (Upper Cretaceous; Australia); and D. spinulosa Alberti 1959 (Oligocene; Germany). All these have distinctive outlines which readily distinguish them from D. wardenensis.
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Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Cerodinium wardenense (Williams and Downie, 1966c) Lentin and Williams, 1987, has an apical and two short antapical horns. Conical apical horn merges imperceptibly into lateral walls. Two antapical horns more positively delimited and straight or slightly diverging. Length of antapical horns approximately equal. Thin walled ovoidal endocyst closely appressed to pericyst except in area of horns. Surface of periphragm with acuminate or blunt short processes, not restricted to sutures of cingulum or sulcus.
Size: pericyst length 46-64 µm, width 43-50 µm, endocyst length 33-41 µm, width 40-46 µm.
Originally Deflandrea, subsequently (and now) Cerodinium; see also Ceratiopsis (combination illegitimate).
Holotype: Williams and Downie, 1966, pl.26, fig.5, Bujak et al., 1980, pl.11, fig.3
Locus typicus: London Clay, Sheppey, Kent, England
Stratum typicum: Eocene
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description as Deflandrea wardenensis: [Williams and Downie, 1966, p. 223]:
Diagnosis:
Cavate cysts, sub-circular to ovoidal periphragm, one apical and two short antapical horns. Conical apical horn merging imperceptibly into lateral walls; two antapical horns more positively delimited and straight or slightly diverging. Length of antapical horns approximately equal. Thin walled ovoidal capsule, closely appressed to periphragm except at horns. Surface of periphragm has short acuminate or blunt processes, not restricted to sutures of cingulum and sulcus. Archaeopyle common.
Description:
The epitract is longer than the hypotract. In outline the former is conical with convex lateral sides, the latter is rounded with the antapical horns being sharply delimited. All three horns can be acuminate but are more commonly blunt. The antapical horns are well separated. The equatorial and longitudinal furrows are both wide with the latter broadening posteriorly. Five postcingulars have been discerned; the rest of the tabulation is too difficult to decipher.
Dimensions:
Holotype: periphragm, length 57 µm, breadth 46 µm; capsule, length 36 µm, breadth 43 µm.
Observed range: periphragm, length 46-64 µm, breadth 43-50 µm, capsule, length 33-41 µm, breadth 40-46 µm.
Affinities:
Species of Deflandrea having processes on the sutures of the cingulum, sulcus and plate boundaries are D. denticulata; D. echinoidea Cookson & Eisenack 1958 (Upper Cretaceous; Australia); and D. spinulosa Alberti 1959 (Oligocene; Germany). All these have distinctive outlines which readily distinguish them from D. wardenensis.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Cerodinium wardenense (Williams and Downie, 1966c) Lentin and Williams, 1987, has an apical and two short antapical horns. Conical apical horn merges imperceptibly into lateral walls. Two antapical horns more positively delimited and straight or slightly diverging. Length of antapical horns approximately equal. Thin walled ovoidal endocyst closely appressed to pericyst except in area of horns. Surface of periphragm with acuminate or blunt short processes, not restricted to sutures of cingulum or sulcus.
Size: pericyst length 46-64 µm, width 43-50 µm, endocyst length 33-41 µm, width 40-46 µm.