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Dichadogonyaulax filapicata
Dichadogonyaulax? filapicata (Gocht, 1970) Jan du Chêne et al., 1986
Now Durotrigia. Originally Gonyaulacysta, subsequently Diacanthum, thirdly Dichadogonyaulax?, fourthly Diacanthum?, fifthly (and now) Durotrigia.
Jan du Chêne et al., 1986, questionably included this species in Dichadogonyaulax.
Holotype: Gocht, 1970, pl.31, fig.1
Locus typicus: Kreis. Grafsch. Diepholz, NW Germany
Stratum typicum: Early Bathonian
Translation Gocht, 1970: LPP
Translation Courtinat, 1989: LPP
Original diagnosis: Gocht, 1970, p.134: Gonyaulacysta filapicanta
Body egg-shaped, thin-walled. Sutural ridges low, partly developed as processes which are connected distally. At the apex the sutural ridges are fused to a "horn", which may be developed net-like or perforate. 4 apical plates , 1-2 very small intercalary plates above the archaeopyle. Plate 1""" within the longitudinal-furrow field, small. 2""" wide but short. 1p elongated and narrow. Longitudinal furrow divided into 7 fields, with distinct flagellar mark. Surface covered with pores and small tubercles. Tabulation: 4" (1-2a), 6"", 6c, 6""", 1p, 1""""; 7s. The dorsal plates 3"" and 4"" develop the archeopyle.
Original description: Gocht, 1970, p.135: Gonyaulacysta filapicanta
Gonyaulacysta belongs to the cyst with gonyaulacean tabulation pattern and archaeopyle type 2P. One of the plates (usually the right one) often remains in situ, but may be partly detached. Involved plates are 3"" and 4"". The apex consists of four plates, of which the ventral 1" is usually elongate rhombiodal, whereas the others are triangular to trapezoidal. At the dorsal margin of 2" and 3" 1 to 2 very small intercalarys have been observed. The precingular plate series consists of 6 trapezoid plates of more or less equal length, the two borgering the longitudinal furrow are slightly smaller. Characteristic is the elongate plate 1p, following the longitudinal furrow, which is always delimited by clear ridges. The girdle is indented; the sutures of the cingular plates follow those of the postcingulars but may be reduced or missing. The postcingular plate 1""" is small and opposite to ra. None of these plates consists of ridges at the margins directing towards the flagellar mark. Antapical field nearly square.
Form of the sutural ridges is variable. Dorsal and lateral they often appear as chains of low, distally connected processes, ventral as nodular, sometimes furcate strings which may be perforate, too. Dorsal sutural ridges weakly developed.
At the apex the sutural ridges are fused to a "horn", which may be developed net-like or perforate.
Surface with funnel-shaped pores and numerous thorn like processes. On bad preserved material the surface is covered by a labyrinth of connected indentions and holes, which may give the impression of a regular ornamentation of the surface.
Supplemental description: Bailey, 1990, p. 135
Subspherical to ovoidal cyst which sometimes exhibit a rounded subpentagonal outline. Acavate, proximate, with primary dorso-ventral flattening. Autophragm with gonyaulacacean paratabulation (Kofoidian formula: 1-2pr, 4", 2a, 6", 6c, 6""", 1p, 1"""") indicated by low, discontinuous ridges and isolated spines which are generally distally linked by thin, smooth trabeculae. Autophragm may be punctate or reticulate, with or without tubercles. Apical hom prominant, comprising a network of fibrous, anastomosing elements representing the fusing of the parasutural ornamentation.
Affinities:
Gocht, 1970, p.135: Gonyaulacysta filapicanta
G. granulata differs from G. filapicata in having an archaeopyle type P and "double" sutural ridges.
Now Durotrigia. Originally Gonyaulacysta, subsequently Diacanthum, thirdly Dichadogonyaulax?, fourthly Diacanthum?, fifthly (and now) Durotrigia.
Jan du Chêne et al., 1986, questionably included this species in Dichadogonyaulax.
Holotype: Gocht, 1970, pl.31, fig.1
Locus typicus: Kreis. Grafsch. Diepholz, NW Germany
Stratum typicum: Early Bathonian
Translation Gocht, 1970: LPP
Translation Courtinat, 1989: LPP
Original diagnosis: Gocht, 1970, p.134: Gonyaulacysta filapicanta
Body egg-shaped, thin-walled. Sutural ridges low, partly developed as processes which are connected distally. At the apex the sutural ridges are fused to a "horn", which may be developed net-like or perforate. 4 apical plates , 1-2 very small intercalary plates above the archaeopyle. Plate 1""" within the longitudinal-furrow field, small. 2""" wide but short. 1p elongated and narrow. Longitudinal furrow divided into 7 fields, with distinct flagellar mark. Surface covered with pores and small tubercles. Tabulation: 4" (1-2a), 6"", 6c, 6""", 1p, 1""""; 7s. The dorsal plates 3"" and 4"" develop the archeopyle.
Original description: Gocht, 1970, p.135: Gonyaulacysta filapicanta
Gonyaulacysta belongs to the cyst with gonyaulacean tabulation pattern and archaeopyle type 2P. One of the plates (usually the right one) often remains in situ, but may be partly detached. Involved plates are 3"" and 4"". The apex consists of four plates, of which the ventral 1" is usually elongate rhombiodal, whereas the others are triangular to trapezoidal. At the dorsal margin of 2" and 3" 1 to 2 very small intercalarys have been observed. The precingular plate series consists of 6 trapezoid plates of more or less equal length, the two borgering the longitudinal furrow are slightly smaller. Characteristic is the elongate plate 1p, following the longitudinal furrow, which is always delimited by clear ridges. The girdle is indented; the sutures of the cingular plates follow those of the postcingulars but may be reduced or missing. The postcingular plate 1""" is small and opposite to ra. None of these plates consists of ridges at the margins directing towards the flagellar mark. Antapical field nearly square.
Form of the sutural ridges is variable. Dorsal and lateral they often appear as chains of low, distally connected processes, ventral as nodular, sometimes furcate strings which may be perforate, too. Dorsal sutural ridges weakly developed.
At the apex the sutural ridges are fused to a "horn", which may be developed net-like or perforate.
Surface with funnel-shaped pores and numerous thorn like processes. On bad preserved material the surface is covered by a labyrinth of connected indentions and holes, which may give the impression of a regular ornamentation of the surface.
Supplemental description: Bailey, 1990, p. 135
Subspherical to ovoidal cyst which sometimes exhibit a rounded subpentagonal outline. Acavate, proximate, with primary dorso-ventral flattening. Autophragm with gonyaulacacean paratabulation (Kofoidian formula: 1-2pr, 4", 2a, 6", 6c, 6""", 1p, 1"""") indicated by low, discontinuous ridges and isolated spines which are generally distally linked by thin, smooth trabeculae. Autophragm may be punctate or reticulate, with or without tubercles. Apical hom prominant, comprising a network of fibrous, anastomosing elements representing the fusing of the parasutural ornamentation.
Affinities:
Gocht, 1970, p.135: Gonyaulacysta filapicanta
G. granulata differs from G. filapicata in having an archaeopyle type P and "double" sutural ridges.