Back
Endoscrinium galeritum
Endoscrinium galeritum (Deflandre, 1938) Vozzhennikova, 1967
Originally Gymnodinium, subsequently Scriniodinium, thirdly (and now) Endoscrinium.
Stover and Evitt, 1978, and Jan du Chêne et al., 1986, retained this species in Scriniodinium Klement, 1957. Lentin and Williams, 1981, 1989, 1993 retained it in Endoscrinium.
Holotype: Deflandre, 1938, pl.5, fig.7-8; Jan du Chêne et al., 1986, pl.104, fig.10-11
Paratype: Deflandre, 1938
Locus typicus: Marnes de Villers-sur-Mer, Calvados, France
Stratum typicum: Oxfordian
Translation Deflandre, 1938, Courtinat, 1989: LPP
Translation Vozzhennikova, 1967: Lees in Sarjeant, 1971
Original description: Deflandre, 1938, p. 167: Gymnodinium galeritum (Note: Deflandre, 1938, depicted his specimens upside down)
Description: The cell bears a relatively straight transverse furrow, which appears to helicoidal on one of the specimens. The longitudinal furow has not been observed. The epitheca has form fo a truncate cone with slightly convex sides and is as large or slightly larger than the hypotheca. At its upper part, a slightly protruding part stands out, in which the membrane of the cyst does not penetrate, and which appears to cover also the apex. The hypotheca is broadly rounded and may present a slight undulation before the antapex. The three specimens I now possess, all bear some folds running from the transverse furrow towards the poles; some of these phenomena are due to the absence of part of the membrane, others are true folds. I do not know whether these aspects are due to fossilization or truely belong to the species.
The dimensions vary: length 78-87 Ám, width 60-65 Ám.
Vozzhennikova, 1967, p. 176: Endoscrinium galeritum
Theca varying from ovoid to polygonal, tabulate with an internal envelope of oval form, divided into two unequal parts. Epitheca shorter than hypotheca, with a acutely pointed apical process. Hypotheca more or less elongated with the antapical part angular or rounded. Plate formula: on the epitheca 3-(4)a + 6np; on the hypotheca 5zd + 0cp" + 0a". Sutures in the form of slightly projecting ribs to the compressed processes. Transverse furrow spiral, its ends separated by a distance equivalent to twice the width of the furrow. Longitudinal furrow extends from the first apical plate to the antapex, extending over the hypotheca. External envelope smooth, finely granular or with an irregularly polygonal network pattern.
Dimensions: Holotype: length 87-78 Ám, breadth 65-60 Ám.
Remarks: Klement (1960) points out that this species bears some general resemblance to Palaeoperidinium dictyophorum Deflandre. The diversity of forms within this species caused Klement (1960) to subdivide it into 3 subspecies: galeritum, fornicatum and reticulatum.
Remark: Courtinat, 1989, p.214
This species presents a strongly granulate endophragm; locally, the granae are developed upwards and form small pillars or spines connecting the endophragm with the periphragm. This connection had been noted on the epicyst (Courtinat in Courtinat and Gaillard, 1980) but it exists also on the hypocyst at the antapical cavation.
Originally Gymnodinium, subsequently Scriniodinium, thirdly (and now) Endoscrinium.
Stover and Evitt, 1978, and Jan du Chêne et al., 1986, retained this species in Scriniodinium Klement, 1957. Lentin and Williams, 1981, 1989, 1993 retained it in Endoscrinium.
Holotype: Deflandre, 1938, pl.5, fig.7-8; Jan du Chêne et al., 1986, pl.104, fig.10-11
Paratype: Deflandre, 1938
Locus typicus: Marnes de Villers-sur-Mer, Calvados, France
Stratum typicum: Oxfordian
Translation Deflandre, 1938, Courtinat, 1989: LPP
Translation Vozzhennikova, 1967: Lees in Sarjeant, 1971
Original description: Deflandre, 1938, p. 167: Gymnodinium galeritum (Note: Deflandre, 1938, depicted his specimens upside down)
Description: The cell bears a relatively straight transverse furrow, which appears to helicoidal on one of the specimens. The longitudinal furow has not been observed. The epitheca has form fo a truncate cone with slightly convex sides and is as large or slightly larger than the hypotheca. At its upper part, a slightly protruding part stands out, in which the membrane of the cyst does not penetrate, and which appears to cover also the apex. The hypotheca is broadly rounded and may present a slight undulation before the antapex. The three specimens I now possess, all bear some folds running from the transverse furrow towards the poles; some of these phenomena are due to the absence of part of the membrane, others are true folds. I do not know whether these aspects are due to fossilization or truely belong to the species.
The dimensions vary: length 78-87 Ám, width 60-65 Ám.
Vozzhennikova, 1967, p. 176: Endoscrinium galeritum
Theca varying from ovoid to polygonal, tabulate with an internal envelope of oval form, divided into two unequal parts. Epitheca shorter than hypotheca, with a acutely pointed apical process. Hypotheca more or less elongated with the antapical part angular or rounded. Plate formula: on the epitheca 3-(4)a + 6np; on the hypotheca 5zd + 0cp" + 0a". Sutures in the form of slightly projecting ribs to the compressed processes. Transverse furrow spiral, its ends separated by a distance equivalent to twice the width of the furrow. Longitudinal furrow extends from the first apical plate to the antapex, extending over the hypotheca. External envelope smooth, finely granular or with an irregularly polygonal network pattern.
Dimensions: Holotype: length 87-78 Ám, breadth 65-60 Ám.
Remarks: Klement (1960) points out that this species bears some general resemblance to Palaeoperidinium dictyophorum Deflandre. The diversity of forms within this species caused Klement (1960) to subdivide it into 3 subspecies: galeritum, fornicatum and reticulatum.
Remark: Courtinat, 1989, p.214
This species presents a strongly granulate endophragm; locally, the granae are developed upwards and form small pillars or spines connecting the endophragm with the periphragm. This connection had been noted on the epicyst (Courtinat in Courtinat and Gaillard, 1980) but it exists also on the hypocyst at the antapical cavation.