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Ctenidodinium continuum
Ctenidodinium continuum Gocht, 1970b, p.141-142, pl.26, fig.3; pl.27, fig.5; pl.29, figs.1-2; pl.32, fig.15; pl.33, fig.8.
Holotype: Gocht, 1970b, pl.32, fig.15.
Locus typicus: Well Aldorf 12, NW Germany
Age: Early Bathonian.
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Ctenidodinium continuum Gocht, 1970b, has a polygonal body, and on the sutures uniformly developed septa of a fine fibrous structure, which are perforate, distally developed into spines (usually short and acuminate) that are not prominent along the cingulum or at the poles. The species is intermediate between C.ornatum and C.pachydermum. The membranes are not as reduced as in C.ornatum on the ventral surface. Unlike C.pachydermum it does not have an apical horn. The anterior margin of the cingulum is much less prominent than the posterior margin. Size: length 66-104 µm, width 65-103 µm.
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Original description: Gocht, 1970, p.141-142
Diagnosis: Body polygonal, sutures bearing rather uniformly developed, finely fibrous crests, which are not more strongly developed at the girdle or at the poles. The tabulation corresponds in all details to that of the type species, C. ornatum.
Dimensions: holotype: 89:90 Ám. Other specimens (about 30) between 66 and 104 Ám long, between 65 and 103 Ám broad.
Affinities:
Gocht, 1970, p. 141-142
Description and affinities (annotated): The species takes an intermediate position between C. ornatum and C. pachydermum. At its sutures and at both sides of the girdle-furrow, the body bears mostly strongly developed crests of uniform height, spanning around the body. Because the epitract is not bell-shaped, like in C. ornatum, and because the accentuation of girdle and poles by means of widely spread septa is absent, the body outline remains closed and whole-edged. Ventrally the septa are somewhat lower than dorsally, but still strongly developed, and not reduced like in C. ornatum.
The septa show a finely fibrous structure, and may be locally perforate, where there is space between the fibres. The distal denticles are sometimes very short; such forms are a transition towards C. pachydermum.
The tabulation corresponds in all details to that of C. ornatum, including the subdivision into separate parts of the longitudinal furrow. SEM studies show broad flagellar marks.
The main differences with C. pachydermum are the absence of the apical horn, the double sutures and the distal denticulation of the septa.
Sarjeant, 1975, p. 56
Although Gocht, 1970 does not comment on this feature, his illustrations (especially pl. 29 figs. 1-2) suggest that the cingular crests are asymmetrical, the posterior margin bearing somewhat higher crests than the anterior margin. For this reason, the species is retained in the genus Ctenidodinium. Since the asymmetry appears less marked than in other species, it is possible that this is an intermediate form linking the two genera.
Holotype: Gocht, 1970b, pl.32, fig.15.
Locus typicus: Well Aldorf 12, NW Germany
Age: Early Bathonian.
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Ctenidodinium continuum Gocht, 1970b, has a polygonal body, and on the sutures uniformly developed septa of a fine fibrous structure, which are perforate, distally developed into spines (usually short and acuminate) that are not prominent along the cingulum or at the poles. The species is intermediate between C.ornatum and C.pachydermum. The membranes are not as reduced as in C.ornatum on the ventral surface. Unlike C.pachydermum it does not have an apical horn. The anterior margin of the cingulum is much less prominent than the posterior margin. Size: length 66-104 µm, width 65-103 µm.
--------------------------------------------------
Original description: Gocht, 1970, p.141-142
Diagnosis: Body polygonal, sutures bearing rather uniformly developed, finely fibrous crests, which are not more strongly developed at the girdle or at the poles. The tabulation corresponds in all details to that of the type species, C. ornatum.
Dimensions: holotype: 89:90 Ám. Other specimens (about 30) between 66 and 104 Ám long, between 65 and 103 Ám broad.
Affinities:
Gocht, 1970, p. 141-142
Description and affinities (annotated): The species takes an intermediate position between C. ornatum and C. pachydermum. At its sutures and at both sides of the girdle-furrow, the body bears mostly strongly developed crests of uniform height, spanning around the body. Because the epitract is not bell-shaped, like in C. ornatum, and because the accentuation of girdle and poles by means of widely spread septa is absent, the body outline remains closed and whole-edged. Ventrally the septa are somewhat lower than dorsally, but still strongly developed, and not reduced like in C. ornatum.
The septa show a finely fibrous structure, and may be locally perforate, where there is space between the fibres. The distal denticles are sometimes very short; such forms are a transition towards C. pachydermum.
The tabulation corresponds in all details to that of C. ornatum, including the subdivision into separate parts of the longitudinal furrow. SEM studies show broad flagellar marks.
The main differences with C. pachydermum are the absence of the apical horn, the double sutures and the distal denticulation of the septa.
Sarjeant, 1975, p. 56
Although Gocht, 1970 does not comment on this feature, his illustrations (especially pl. 29 figs. 1-2) suggest that the cingular crests are asymmetrical, the posterior margin bearing somewhat higher crests than the anterior margin. For this reason, the species is retained in the genus Ctenidodinium. Since the asymmetry appears less marked than in other species, it is possible that this is an intermediate form linking the two genera.