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Gonyaulacysta dangeardii
Gonyaulacysta dangeardii Sarjeant, 1968, p.226–227, pl.1, fig.21; pl.3, figs.8,15; text-fig.3. Emendation: Sarjeant, 1982b, p.42–43, as Tubotuberella dangeardii.
Now Tubotuberella. Originally Gonyaulacysta, subsequently Dimidiadinium, thirdly (and now) Tubotuberella.
Holotype: Sarjeant, 1968, pl.3, fig.8; text-fig.3; Sarjeant, 1982b, text-figs.5c–d; Jan du Chêne et al., 1986a, pl.127, figs.4–7; Fensome et al., 1993a, figs.1,3–4 — p.1089; figs.1,4–5 — p.1093.
Locus typicus: Villers-sur-Mer, Calvados, France
Stratum typicum: Oxfordian
Original description: Sarjeant, 1968, p. 226-227
Diagnosis: A species of Gonyaulacysta having a theca of approximately pentagonal outline. The endophragm and periphragm are generally in contact, but the peripharagm is detached in three places: at the apex, where it forms a short, blunt apical horn; along the line of the cingulum; and at the antapex, where an antapical pericoel is present. Tabulation 4", ?0a, 6"", ?6c, 6""", 1p, 1""""; sutures marked by low ridges which very occasionally bear minute spinelets. Cingulum narrow, strongly laevo-rotatory: sulcus broader, extending onto the epitract.
Description: The roughly pentagonal outline results from the outbulge of the periphragm along the line of the cingulum. This divides the shell into an approximately hemispherical epitract (surmounted, and given angularity, by the apical horn) and a hypotract in the form of a truncated cone, the antapex being quite flat. The first apical plate is elongate and occupies the anterior prolongation of the sulcus: the three other plates are smaller. No anterior intercalary plate appears to be present; the six precingular plates are therefore of almost equal size, plate 3"" being typically lost in archaeopyle formation. Six postcingular plates were present, the first being reduced to accomodate an almost triangular posterior intercalary plate. The antapex is occupied by a single polygonal plate situated exactly at right angels to the long axis of the shell. The positions of the sutures subdividing it were difficult to determine, but six cingular plates are thought to be present. The sulcus, roughly twice as broad as the cingulum, lacks subdivisions. The relatively thin wall was frequently folded in some measure, enhancing the difficulty of determining the tabulation: in the holotype, folding of the hypotract obscured the position of the boundary between plates 1""" and 1p.
Dimensions: Holotype: overall length 70 Ám, breadth 50 Ám; length of apical horn 7 Ám; length of antapical pericoel 12.5 Ám breadth of endophragm 45 Ám.
Range: overall length 70-89 Ám , breadth 40-55 Ám; length of apical horn 4-8 Ám; length of antapical pericoel 9-14 Ám; breadth of endophragm 38-53 Ám.
Now Tubotuberella. Originally Gonyaulacysta, subsequently Dimidiadinium, thirdly (and now) Tubotuberella.
Holotype: Sarjeant, 1968, pl.3, fig.8; text-fig.3; Sarjeant, 1982b, text-figs.5c–d; Jan du Chêne et al., 1986a, pl.127, figs.4–7; Fensome et al., 1993a, figs.1,3–4 — p.1089; figs.1,4–5 — p.1093.
Locus typicus: Villers-sur-Mer, Calvados, France
Stratum typicum: Oxfordian
Original description: Sarjeant, 1968, p. 226-227
Diagnosis: A species of Gonyaulacysta having a theca of approximately pentagonal outline. The endophragm and periphragm are generally in contact, but the peripharagm is detached in three places: at the apex, where it forms a short, blunt apical horn; along the line of the cingulum; and at the antapex, where an antapical pericoel is present. Tabulation 4", ?0a, 6"", ?6c, 6""", 1p, 1""""; sutures marked by low ridges which very occasionally bear minute spinelets. Cingulum narrow, strongly laevo-rotatory: sulcus broader, extending onto the epitract.
Description: The roughly pentagonal outline results from the outbulge of the periphragm along the line of the cingulum. This divides the shell into an approximately hemispherical epitract (surmounted, and given angularity, by the apical horn) and a hypotract in the form of a truncated cone, the antapex being quite flat. The first apical plate is elongate and occupies the anterior prolongation of the sulcus: the three other plates are smaller. No anterior intercalary plate appears to be present; the six precingular plates are therefore of almost equal size, plate 3"" being typically lost in archaeopyle formation. Six postcingular plates were present, the first being reduced to accomodate an almost triangular posterior intercalary plate. The antapex is occupied by a single polygonal plate situated exactly at right angels to the long axis of the shell. The positions of the sutures subdividing it were difficult to determine, but six cingular plates are thought to be present. The sulcus, roughly twice as broad as the cingulum, lacks subdivisions. The relatively thin wall was frequently folded in some measure, enhancing the difficulty of determining the tabulation: in the holotype, folding of the hypotract obscured the position of the boundary between plates 1""" and 1p.
Dimensions: Holotype: overall length 70 Ám, breadth 50 Ám; length of apical horn 7 Ám; length of antapical pericoel 12.5 Ám breadth of endophragm 45 Ám.
Range: overall length 70-89 Ám , breadth 40-55 Ám; length of apical horn 4-8 Ám; length of antapical pericoel 9-14 Ám; breadth of endophragm 38-53 Ám.