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Glaphyrosphaera glabra
Glaphyrosphaera glabra Schiøler and Wilson, 1994, p.142-144, figs.2A-J,3A-D,4A-B,5,6A-B.
Taxonomic senior synonym: Thalassiphora (as and now Wilsonisphaera) petila, according to Schiøler and Wilson (1995, p.511). The name Glaphyrosphaera glabra was not validly published in Slimani (1994, p.68), who cited it in synonymy as an unpublished thesis name.
Holotype: Schiøler and Wilson, 1994, figs.2B,6A-B.
Age: Maastrichtian.
Original diagnosis: Schioler and Wilson, 1994
A holocavate gonyaulacold cyst wlth a laterally compressed thin-walled pericyst and an ovoid laterally compressed endocyst joined by a funnel-shaped process that connects the midventral areas. The process is attached to the endophragm, flares distally trumpate and merges into the periphragm. Some of the larger paraplates and the paracingulum are indicated by low parasutural ridges on the periphragm. Some of the parasutural ridges are faintly serrate. The periarcheopyle is large and angular, type P (3""). Two different]y shaped hollow processes arise from the endoperculum: one process is irregularly bifid or trifid distally, the other is digitate distally.
Description:
Laterally compressed holocavate cyst with a large pericyst and a much smaller spherical or ovoidal endocyst. The pericyst and endocyst are separated by a large pericoel except in the sulcal area. where they are connected by a funnelshaped process. Width of pericoel: 10-14 µm. The periphragm appears smooth at normal magnification, but is microgranular in high magnification, and has low serrate parasutural ridges (Fig. 3D). The apex is indicated by a short protrusion (length: 1-3 µm). The periarcheopyle is broad and large and the perioperculum is free. The endophragm is smooth and connected to the periphragm by a hollow trumpate process (process length 5-15 µm). The process arises from the midventral surface of the endocyst, broadens distally and merges into the midventral part of the periphragm (Figs. 2A-D. 4B, 6B). The endophragm protrudes slightly into the process cavity forming a small bulge (Figs. 2A, B, D, G. H; 4B; 6B) at the proximal attachment of the process. A small bulge is sometimes seen at the apical end of the endocyst. The endoperculum is commonly found attached or in place (Figs. 2A,D. F, I,J; 4A,B). Two hollow digitate processes (length c. 20 Ám) extend from the endoperculum towards the periarcheopyle. One process is irregularly bifid or bifid distally, the other is spatulate and digitate distally, broadening into 5-10 small spines (Fig. 2D,F.I,J). The former process apparently extends from the anterior part of the endoperculum, whereas the latter process seems to extend from the posterior part. The tabulation is gonyaulacoid, partially expressed by low ridges on the periphragm. Probable Kofoid formula (Taylor-Evitt formula in parentheses): 4", (A-C, 1u), 6"" (1i, 2-6), 6c (au-fi), 6""" (Iu-VI), ?s, ?p, 1""""(Y). The archeopyle type is P (3"") in both the endophragm and the periphragm. The paracingulum is indicated by low sutural ridges on the periphragm and sometimes by equatorial folds in the endophragm.
The original shape of the cyst is probably lenticular as all observed specimens are laterally compressed. The exact relationship between the two digitate processes on the endoperculum and the perioperculum could not be determined as all observed specimens have lost the perioperculum: however it is probable that the processes were in contact with the perioperculum before excystment, thereby serving as additional support for the endocyst.
Dimensions: diameter of periphragm holotype 99, range 86 (93) 110 µm, length of endocyst holotype 61 µm, range 46 (55) 67 µm, width of endocyst holotype 18 µm, range 38 (44) 57 µm. Number of specimens measured: 14.
Schioler and Wilson, 1994, p. 139:
Several new dinoflagellate taxa were reported by the second author during a palynological study of Danish Maastrichtian chalk sections (Wilson 1971, 1974); one was described informally as "Glaphyrosphaera" (type species "Glaphyrosphaera glabra" Wilson, 1974). A recent palynological study of core samples of Maastrichtian-Danian chalk from eight Danish offshore wells (Schioler & Wilson 1993) and one onshore well has confirmed the presence of Glaphyrosphaera glabra gen. et sp. nov. in the Maastrichtian interval. The taxon has been restudied, and significant new details are added to the original description. Specimens from the new Danish subsurface material have been compared with Wilson"s specimens from Danish outcrop sections, and the identity has been confirmed. A formal description of Glaphyrosphaera glabra gen. et sp. nov. is given.
Taxonomic senior synonym: Thalassiphora (as and now Wilsonisphaera) petila, according to Schiøler and Wilson (1995, p.511). The name Glaphyrosphaera glabra was not validly published in Slimani (1994, p.68), who cited it in synonymy as an unpublished thesis name.
Holotype: Schiøler and Wilson, 1994, figs.2B,6A-B.
Age: Maastrichtian.
Original diagnosis: Schioler and Wilson, 1994
A holocavate gonyaulacold cyst wlth a laterally compressed thin-walled pericyst and an ovoid laterally compressed endocyst joined by a funnel-shaped process that connects the midventral areas. The process is attached to the endophragm, flares distally trumpate and merges into the periphragm. Some of the larger paraplates and the paracingulum are indicated by low parasutural ridges on the periphragm. Some of the parasutural ridges are faintly serrate. The periarcheopyle is large and angular, type P (3""). Two different]y shaped hollow processes arise from the endoperculum: one process is irregularly bifid or trifid distally, the other is digitate distally.
Description:
Laterally compressed holocavate cyst with a large pericyst and a much smaller spherical or ovoidal endocyst. The pericyst and endocyst are separated by a large pericoel except in the sulcal area. where they are connected by a funnelshaped process. Width of pericoel: 10-14 µm. The periphragm appears smooth at normal magnification, but is microgranular in high magnification, and has low serrate parasutural ridges (Fig. 3D). The apex is indicated by a short protrusion (length: 1-3 µm). The periarcheopyle is broad and large and the perioperculum is free. The endophragm is smooth and connected to the periphragm by a hollow trumpate process (process length 5-15 µm). The process arises from the midventral surface of the endocyst, broadens distally and merges into the midventral part of the periphragm (Figs. 2A-D. 4B, 6B). The endophragm protrudes slightly into the process cavity forming a small bulge (Figs. 2A, B, D, G. H; 4B; 6B) at the proximal attachment of the process. A small bulge is sometimes seen at the apical end of the endocyst. The endoperculum is commonly found attached or in place (Figs. 2A,D. F, I,J; 4A,B). Two hollow digitate processes (length c. 20 Ám) extend from the endoperculum towards the periarcheopyle. One process is irregularly bifid or bifid distally, the other is spatulate and digitate distally, broadening into 5-10 small spines (Fig. 2D,F.I,J). The former process apparently extends from the anterior part of the endoperculum, whereas the latter process seems to extend from the posterior part. The tabulation is gonyaulacoid, partially expressed by low ridges on the periphragm. Probable Kofoid formula (Taylor-Evitt formula in parentheses): 4", (A-C, 1u), 6"" (1i, 2-6), 6c (au-fi), 6""" (Iu-VI), ?s, ?p, 1""""(Y). The archeopyle type is P (3"") in both the endophragm and the periphragm. The paracingulum is indicated by low sutural ridges on the periphragm and sometimes by equatorial folds in the endophragm.
The original shape of the cyst is probably lenticular as all observed specimens are laterally compressed. The exact relationship between the two digitate processes on the endoperculum and the perioperculum could not be determined as all observed specimens have lost the perioperculum: however it is probable that the processes were in contact with the perioperculum before excystment, thereby serving as additional support for the endocyst.
Dimensions: diameter of periphragm holotype 99, range 86 (93) 110 µm, length of endocyst holotype 61 µm, range 46 (55) 67 µm, width of endocyst holotype 18 µm, range 38 (44) 57 µm. Number of specimens measured: 14.
Schioler and Wilson, 1994, p. 139:
Several new dinoflagellate taxa were reported by the second author during a palynological study of Danish Maastrichtian chalk sections (Wilson 1971, 1974); one was described informally as "Glaphyrosphaera" (type species "Glaphyrosphaera glabra" Wilson, 1974). A recent palynological study of core samples of Maastrichtian-Danian chalk from eight Danish offshore wells (Schioler & Wilson 1993) and one onshore well has confirmed the presence of Glaphyrosphaera glabra gen. et sp. nov. in the Maastrichtian interval. The taxon has been restudied, and significant new details are added to the original description. Specimens from the new Danish subsurface material have been compared with Wilson"s specimens from Danish outcrop sections, and the identity has been confirmed. A formal description of Glaphyrosphaera glabra gen. et sp. nov. is given.