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Durotrigia
From Williams et al., 2017:
[Durotrigia, Bailey, 1987, p. 89, 91, 94
Nomenclatural junior synonym: Baileyella. Özdikmen (2009, p.234) considered Durotrigia Bailey to be illegitimate because it is a junior homonym of Durotrigia Hoffstetter, 1967; however, Durotrigia Hoffstetter is an animal and under the I.C.N. it does not pre-empt Durotrigia Bailey.
Type Species: Durotrigia daveyi, Bailey, 1987 (pl.2, figs.1 ,4 ,9)]
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Original description: [Bailey, 1987]:
Diagnosis:
Cyst subspherical, proximate or proximochorate. Gonyaulacacean tabulation: (1acl, 1pr, 4`, 2a, 6``, 6c, 6```, 1p, 1````, 5s, flagellar pore area).
The archaeopyle is formed by the loss of 1 to 5 precingular plates (1P-5P). The autophragm is well tabulated, with distinct sutural ridges surmounted by isolated projections and/or crests, which may be perforate.
Description:
Shape: Cyst subspherical.
Wall relationships: Autophragm only.
Wall features: Sutural features include low ridges, usually surmounted by isolated projections and/or denticulate crests which may be perforate. The spines/denticulations may be distally bifurcate, and tend to be more complex about the cingulum and antapical pole. Gonal spines are also large. The autophragm has a complex structure (see Bailey, 1987, pl.1, fig.5), appearing scabrate in transmitted light.
Tabulation: Indicated by variable, but distinct sutural features.
Gonyaulacacean formula: 1acl, 1pr, 4`, 2a, 6``, 6c, 6```, 1p, 1````, 5s, flagellar pore area.
Archaeopyle: Precingular, formed by the loss of up to five precingular plates. Cysts with varying dehiscence; 1P, 2P, 3P, 4P and 5P. The most common type is 4P, with the first and sixth precingulars remaining attached, forming a broad isthmus joining the apical series to the hypocyst. Excystment begins dorsally at the 3" plate and progresses ventrally in both directions.
Cingulum: Indicated by six rectangular plates. Cingular sutures often carry complex denticulate crests which may be perforate and bear bifurcate spines (Fig.2c). Ornamentation is symmetrical about the cingulum.
Sulcus: Clearly discernible. The innermost part of the sulcus is occupied by a large flagellar pore area where no detail can be distinguished. Surrounding this area are five sulcal plates; as, ras, rs, ps, ls ([Bailey, 1987] Fig.2d).
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Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Durotrigia Bailey, 1987. Diagnosis from Bailey (1987, p.89). Cyst subspherical, proximate or proximochorate. Gonyaulacacean tabulation: (lacl, 1pr, 4`, 2a, 6", 6c, 6"' , 1p, 1"'' , 5s, flagellar pore area). The archeopyle is formed by the loss of 1 to 5 precingular plates (1P-5P). The autophragm is well tabulated with distinct sutural ridges surmounted by isolated projections and/or crests, which may be perforate.
[Durotrigia, Bailey, 1987, p. 89, 91, 94
Nomenclatural junior synonym: Baileyella. Özdikmen (2009, p.234) considered Durotrigia Bailey to be illegitimate because it is a junior homonym of Durotrigia Hoffstetter, 1967; however, Durotrigia Hoffstetter is an animal and under the I.C.N. it does not pre-empt Durotrigia Bailey.
Type Species: Durotrigia daveyi, Bailey, 1987 (pl.2, figs.1 ,4 ,9)]
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Bailey, 1987]:
Diagnosis:
Cyst subspherical, proximate or proximochorate. Gonyaulacacean tabulation: (1acl, 1pr, 4`, 2a, 6``, 6c, 6```, 1p, 1````, 5s, flagellar pore area).
The archaeopyle is formed by the loss of 1 to 5 precingular plates (1P-5P). The autophragm is well tabulated, with distinct sutural ridges surmounted by isolated projections and/or crests, which may be perforate.
Description:
Shape: Cyst subspherical.
Wall relationships: Autophragm only.
Wall features: Sutural features include low ridges, usually surmounted by isolated projections and/or denticulate crests which may be perforate. The spines/denticulations may be distally bifurcate, and tend to be more complex about the cingulum and antapical pole. Gonal spines are also large. The autophragm has a complex structure (see Bailey, 1987, pl.1, fig.5), appearing scabrate in transmitted light.
Tabulation: Indicated by variable, but distinct sutural features.
Gonyaulacacean formula: 1acl, 1pr, 4`, 2a, 6``, 6c, 6```, 1p, 1````, 5s, flagellar pore area.
Archaeopyle: Precingular, formed by the loss of up to five precingular plates. Cysts with varying dehiscence; 1P, 2P, 3P, 4P and 5P. The most common type is 4P, with the first and sixth precingulars remaining attached, forming a broad isthmus joining the apical series to the hypocyst. Excystment begins dorsally at the 3" plate and progresses ventrally in both directions.
Cingulum: Indicated by six rectangular plates. Cingular sutures often carry complex denticulate crests which may be perforate and bear bifurcate spines (Fig.2c). Ornamentation is symmetrical about the cingulum.
Sulcus: Clearly discernible. The innermost part of the sulcus is occupied by a large flagellar pore area where no detail can be distinguished. Surrounding this area are five sulcal plates; as, ras, rs, ps, ls ([Bailey, 1987] Fig.2d).
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Durotrigia Bailey, 1987. Diagnosis from Bailey (1987, p.89). Cyst subspherical, proximate or proximochorate. Gonyaulacacean tabulation: (lacl, 1pr, 4`, 2a, 6", 6c, 6"' , 1p, 1"'' , 5s, flagellar pore area). The archeopyle is formed by the loss of 1 to 5 precingular plates (1P-5P). The autophragm is well tabulated with distinct sutural ridges surmounted by isolated projections and/or crests, which may be perforate.