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Lithodinia pertusa ssp. heta
Lithodinia pertusa "subsp. heta" (Below, 1981a, p.56-57, pl.3, figs.7a-b,8a-b; pl.11, fig.21; pl.14, figs.1-4; text-figs.59a-b,60) Williams et al., 1993, p.55.
Holotype: Below, 1981a, pl.3, figs.8a-b; Fensome et al., 1991, figs. 3-4 - p.647; figs.4-5 - p.709.
OW Meiourogonyaulax pertusa subsp. heta. Originally (and now) Meiourogonyaulax pertusa subsp. heta, subsequently Lithodinia pertusa subsp. heta.
Age: Hauterivian
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Original description: [Below, 1981]:
Meiourogonyaulax pertusa (DUXBURY 1977) comb. nov. ssp. heta, n. ssp.
Etymology: From arabic "heta" = the wall; referring to the high, parasutural septa.
Holotype: Mount XV-4 720 8/20.
Paratype: Mount XII-4720 6/8.
Type location: Profile EB, Profile depth 13.00 m; Yahia ou Said.
Type stratum: Upper Hauterivian.
Diagnosis: Spheroid, two-layered cyst. Cyst wall in transmitted light spuriously coarsely perforate. Paratabulation 4', 6", XC, 6'", pc, 1"", ra, rs, ls, ps. Parasutures as high muri. Archaeopyle "enlarged", apical, Ā.
Description:
More common than the forms with the low, parasutural costae that are typical for Meiourogonyaulax pertusa (DUXBURY 1977) comb. nov. ssp. pertusa, specimens with high, perforate, parasutural septa are common in the Moroccan material, They are delimited as an independent subspecies.
In transmitted light the cyst walls of the spheroid cyst and the parasutural costae appear to be perforate. The perforations have different shapes . Oval, slit-like , narrowed, circular, large and small perforations of the membrane are usually separated by wide bridges. SEM studies confirm the two-walled condition of the species. Periphragm and endophragm are smooth (Plate 14, Figs. 4, 2); consequently, the apparent perforation of the periphragm should be attributed to the reticulate arrangement of the ?endophragmal filler in the lumen between both membranes. High, distally rounded, parasutural septa, particularly emphasized antapically, are formed by the periphragm. They divide the cyst according to the goniaulacoidal pattern into 4', 6", Xc, 6'", pc, 1"", ra, rs, ls, ps (Text Figs. 59, 60). 1' follows anteriorly to as against which it is only incompletely delimited. The position of this parasuture becomes visible only if the operculum has been dislocated. Of the approximately equally large precingulars, 6" is at best separated by a fine line from as. This applies also to the narrow, long first postcingular. However, because
ls is deeply dented into the cyst, 1"" can be clearly identified. ps, rs and ra are separated against each other and against pc, 1"", 6"' but not against ls. The spiral paracingulun is offset at the parasulcus by twice its width and is only indistinctly divided into individual paracingular paraplates.
The archaeopyle is apical and must be called "enlarged" sensu Evitt. The septa between the apical and the precingular fringe of paraplates
are usually on the operculum and are removed during emergence.
Measurements:
Holotype: length 70 μ; width 61 μ; length of appendages 4-7.5 μ; width of paracingulum 4.5-5 μ; ends of paracingulum are offset by 8 μ.
Other specimens: total length 72-90 μ (mean 76 μ); total width 60-78 μ (mean 69 μ); height of appendages 3-9 μ.
Material examined: 33 specimens.
Distribution: Profile EB (20): Hauterivian; Profile Chichaoua 1 (7): Hauterivian.
Holotype: Below, 1981a, pl.3, figs.8a-b; Fensome et al., 1991, figs. 3-4 - p.647; figs.4-5 - p.709.
OW Meiourogonyaulax pertusa subsp. heta. Originally (and now) Meiourogonyaulax pertusa subsp. heta, subsequently Lithodinia pertusa subsp. heta.
Age: Hauterivian
---------------------------------------------------------------------------------------------------------------
Original description: [Below, 1981]:
Meiourogonyaulax pertusa (DUXBURY 1977) comb. nov. ssp. heta, n. ssp.
Etymology: From arabic "heta" = the wall; referring to the high, parasutural septa.
Holotype: Mount XV-4 720 8/20.
Paratype: Mount XII-4720 6/8.
Type location: Profile EB, Profile depth 13.00 m; Yahia ou Said.
Type stratum: Upper Hauterivian.
Diagnosis: Spheroid, two-layered cyst. Cyst wall in transmitted light spuriously coarsely perforate. Paratabulation 4', 6", XC, 6'", pc, 1"", ra, rs, ls, ps. Parasutures as high muri. Archaeopyle "enlarged", apical, Ā.
Description:
More common than the forms with the low, parasutural costae that are typical for Meiourogonyaulax pertusa (DUXBURY 1977) comb. nov. ssp. pertusa, specimens with high, perforate, parasutural septa are common in the Moroccan material, They are delimited as an independent subspecies.
In transmitted light the cyst walls of the spheroid cyst and the parasutural costae appear to be perforate. The perforations have different shapes . Oval, slit-like , narrowed, circular, large and small perforations of the membrane are usually separated by wide bridges. SEM studies confirm the two-walled condition of the species. Periphragm and endophragm are smooth (Plate 14, Figs. 4, 2); consequently, the apparent perforation of the periphragm should be attributed to the reticulate arrangement of the ?endophragmal filler in the lumen between both membranes. High, distally rounded, parasutural septa, particularly emphasized antapically, are formed by the periphragm. They divide the cyst according to the goniaulacoidal pattern into 4', 6", Xc, 6'", pc, 1"", ra, rs, ls, ps (Text Figs. 59, 60). 1' follows anteriorly to as against which it is only incompletely delimited. The position of this parasuture becomes visible only if the operculum has been dislocated. Of the approximately equally large precingulars, 6" is at best separated by a fine line from as. This applies also to the narrow, long first postcingular. However, because
ls is deeply dented into the cyst, 1"" can be clearly identified. ps, rs and ra are separated against each other and against pc, 1"", 6"' but not against ls. The spiral paracingulun is offset at the parasulcus by twice its width and is only indistinctly divided into individual paracingular paraplates.
The archaeopyle is apical and must be called "enlarged" sensu Evitt. The septa between the apical and the precingular fringe of paraplates
are usually on the operculum and are removed during emergence.
Measurements:
Holotype: length 70 μ; width 61 μ; length of appendages 4-7.5 μ; width of paracingulum 4.5-5 μ; ends of paracingulum are offset by 8 μ.
Other specimens: total length 72-90 μ (mean 76 μ); total width 60-78 μ (mean 69 μ); height of appendages 3-9 μ.
Material examined: 33 specimens.
Distribution: Profile EB (20): Hauterivian; Profile Chichaoua 1 (7): Hauterivian.