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Microdinium deconinckii
Microdinium deconinckii Slimani, 1994, p.32-33, pl.3, fig.30; pl.5, figs.1-2,5-8,23-24.
Holotype: Slimani, 1994, pl.5, figs.1-2,5-6.
Age: Early Campanian-earliest Danian
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Original description (Slimani, 1994) (translated from French):
Microdinium deconinckii sp. nov.
(Pl. 3, Fig.30; PI.5, Fig.1,2,5-8,23,24)
Derivation of the name: In honor of Dr. Jan DE CONINCK, Universiteit Gent, Geologisch Instituut, Laboratorium voor Paléontologie, Belgium.
Holotvpe: Halembaye ech. I. preparation 6, coordinate. E.F. B30.
Paratvpe 1: Turnhout -933 m, preparation 1, E.F. F26/4 - F27/5.
Paratvpe 2: Turnhout -933 m, preparation 6, coord. E.F. E48/4.
Type locality: Halembaye ex. 1.
Type horizon: Campanian (Vaals Formation).
Synonymy:
?1967: Ceratocorys vetigera (DEFLANDRE, 1937b) - VOZZHENNIKOVA, pl. 35, fig. 1-2, 5, pl. 36, fig. 3.
?1967: Ceratocorys smolenskiense - VOZZHENNIKOVA, pl. 35, fig. 6. 71967: Microdinium sp. - VOZZHENNIKOVA, pl. 35, fig. 7, pl. 37, fig. 6.
?1974: Microdinium veligerum in WILSON, pl. 12, fig. 8-9.
Diagnosis: Small, proximal, suturocavate, ovoid to spheroidal cyst with an epicyst the same length as the hypocyst or slightly smaller. It is characterized by glabrous suturocavate ridges and spongy, dotted to slightly granulated intratabular areas. The paratabulation is of the partiform gonyaulacoid type and corresponds to the following formula: 1pr, 4', 4a, 7", 7c, 6"', 1p, 1"", 2 -4s. The archaeopyle is apical and intercalary, of type (tAtl)a, with a ventrally attached operculum.
Dimensions: Holotype: maximum diameter: 36 µm. Variations: maximum diameter: 30-40 µm.
Number of specimens measured: 22.
Material: > 40 specimens.
Description: The endophragm (approximately 2 µm thick) is spongy in the intratabular areas where it is adjacent to the periphragm, which is thin and transparent. The ridges (2 to 5 µm high) are glabrous and rounded. The paracingulum (6-10 µm wide) is non-spiral to very slightly laevorotatory. The parasulcus is composed of 2 to 4 sulcal paraplates, of which the posterior paraplate is the widest and omega-shaped. The operculum is composed of 4 apical paraplates, 4 anterior intercalary paraplates, and one preapical paraplate.
Discussion and comparison: Although the species studied has fairly well-developed ridges, it is far from being attributable to Rhiptocorys LEJEUNE - CARPENTIER and SARJEANT (1983), emended in the present work, as it has an epicyst of the same length or slightly shorter than the hypocyst and bearing parasutural ridges comparable to the paracingulate and hypocystal ridges. It is therefore attributable to the genus Microdinium. Microdinium deconinckii sp. nov. is very similar to the cysts named ?Microdinium veligera in WILSON (1974, pl. 12, fig. 8-9), and probably, to Microdinium sp. in VOZZHENNIKOV A (1967) and some specimens of Ceratocorys smolenskiense VOZZHENNIKOVA (1967) (see synonymy above) from the Upper Cretaceous of Smolensk, USSR. Microdinium granocarinatum (BELOW, 1987b) LENTIN and WILLIAMS (1989) is a species which also bears suturocavate crests but they are lower and distally denticulate. Microdinium irregulare CLARKE and VERDIER (1967), considered a junior synonym of R. veligera by BELOW (1987b: p. 65), is more densely ornamented with intratabular granules or warts and bears wavy ridges. Microdinium parvum sp. nov. (in this work) is much smaller with a densely granulated intratabular surface and lower ridges. Microdinium carpentieriae sp. nov. lacks cingulate ridges and bears more developed suturocavate ridges with an acute, lumpy to gratinate distal margin.
Stratigraphic distribution: Beutenaken: sample 1, Halembaye: sample 1; Lower Campanian (G. quadrata Zone). Turnhout: -987 to -759.89 m, Lower Campanian. - end of upper Maastrichtian, beginning of Danian.
Holotype: Slimani, 1994, pl.5, figs.1-2,5-6.
Age: Early Campanian-earliest Danian
------------------------------------------------------------------------------------------------------------------------------------------------------
Original description (Slimani, 1994) (translated from French):
Microdinium deconinckii sp. nov.
(Pl. 3, Fig.30; PI.5, Fig.1,2,5-8,23,24)
Derivation of the name: In honor of Dr. Jan DE CONINCK, Universiteit Gent, Geologisch Instituut, Laboratorium voor Paléontologie, Belgium.
Holotvpe: Halembaye ech. I. preparation 6, coordinate. E.F. B30.
Paratvpe 1: Turnhout -933 m, preparation 1, E.F. F26/4 - F27/5.
Paratvpe 2: Turnhout -933 m, preparation 6, coord. E.F. E48/4.
Type locality: Halembaye ex. 1.
Type horizon: Campanian (Vaals Formation).
Synonymy:
?1967: Ceratocorys vetigera (DEFLANDRE, 1937b) - VOZZHENNIKOVA, pl. 35, fig. 1-2, 5, pl. 36, fig. 3.
?1967: Ceratocorys smolenskiense - VOZZHENNIKOVA, pl. 35, fig. 6. 71967: Microdinium sp. - VOZZHENNIKOVA, pl. 35, fig. 7, pl. 37, fig. 6.
?1974: Microdinium veligerum in WILSON, pl. 12, fig. 8-9.
Diagnosis: Small, proximal, suturocavate, ovoid to spheroidal cyst with an epicyst the same length as the hypocyst or slightly smaller. It is characterized by glabrous suturocavate ridges and spongy, dotted to slightly granulated intratabular areas. The paratabulation is of the partiform gonyaulacoid type and corresponds to the following formula: 1pr, 4', 4a, 7", 7c, 6"', 1p, 1"", 2 -4s. The archaeopyle is apical and intercalary, of type (tAtl)a, with a ventrally attached operculum.
Dimensions: Holotype: maximum diameter: 36 µm. Variations: maximum diameter: 30-40 µm.
Number of specimens measured: 22.
Material: > 40 specimens.
Description: The endophragm (approximately 2 µm thick) is spongy in the intratabular areas where it is adjacent to the periphragm, which is thin and transparent. The ridges (2 to 5 µm high) are glabrous and rounded. The paracingulum (6-10 µm wide) is non-spiral to very slightly laevorotatory. The parasulcus is composed of 2 to 4 sulcal paraplates, of which the posterior paraplate is the widest and omega-shaped. The operculum is composed of 4 apical paraplates, 4 anterior intercalary paraplates, and one preapical paraplate.
Discussion and comparison: Although the species studied has fairly well-developed ridges, it is far from being attributable to Rhiptocorys LEJEUNE - CARPENTIER and SARJEANT (1983), emended in the present work, as it has an epicyst of the same length or slightly shorter than the hypocyst and bearing parasutural ridges comparable to the paracingulate and hypocystal ridges. It is therefore attributable to the genus Microdinium. Microdinium deconinckii sp. nov. is very similar to the cysts named ?Microdinium veligera in WILSON (1974, pl. 12, fig. 8-9), and probably, to Microdinium sp. in VOZZHENNIKOV A (1967) and some specimens of Ceratocorys smolenskiense VOZZHENNIKOVA (1967) (see synonymy above) from the Upper Cretaceous of Smolensk, USSR. Microdinium granocarinatum (BELOW, 1987b) LENTIN and WILLIAMS (1989) is a species which also bears suturocavate crests but they are lower and distally denticulate. Microdinium irregulare CLARKE and VERDIER (1967), considered a junior synonym of R. veligera by BELOW (1987b: p. 65), is more densely ornamented with intratabular granules or warts and bears wavy ridges. Microdinium parvum sp. nov. (in this work) is much smaller with a densely granulated intratabular surface and lower ridges. Microdinium carpentieriae sp. nov. lacks cingulate ridges and bears more developed suturocavate ridges with an acute, lumpy to gratinate distal margin.
Stratigraphic distribution: Beutenaken: sample 1, Halembaye: sample 1; Lower Campanian (G. quadrata Zone). Turnhout: -987 to -759.89 m, Lower Campanian. - end of upper Maastrichtian, beginning of Danian.