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Durotrigia daveyi
Durotrigia daveyi Bailey, 1987
Originally (and now) Durotrigia, subsequently Baileyella (generic name illegitimate).
Holotype: Bailey, 1987, pl.2, figs.1,4,9; Fensome et al., 1993, p.1095, figs.1-2
Paratype: Bailey, 1987
Locus typicus: British Geological Survey borehole 50/03 329, Lyme Bay, southern England
Stratum typicum: Sauzei Zone, Early Bajocian
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Durotrigia daveyi Bailey, 1987. The sutural features include low ridges usually surmounted by isolated projections and or denticulate crests which may be perforate. The spines or 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 appearing scabrate in transmitted light. The archeopyle is precingular formed from the loss of up to 5 plates. The most common type is 4P, with the first and sixth plates remaining attached. Excystment begins dorsally at the 3" and progresses ventrally in both directions. There are six cingular plates with often complex denticulate crests, which may be perforate and bear bifurcate spines. The sulcal plates are discernible. Note Diacanthum has a variable archeopyle (1-3P). Occisucysta and Tehamadinium have 2P archeopyles (2",3"). Liesbergia has a P or 2P archeopyle (3", 4") and has trabeculate parasutural ornamentation. Bailey (1987) did not give any details on the size of the specimens examined.
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Original diagnosis: Bailey, 1987, p.89
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.
Original description: Bailey, 1987, p.91
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 ([Bailey, 1987] 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.
Originally (and now) Durotrigia, subsequently Baileyella (generic name illegitimate).
Holotype: Bailey, 1987, pl.2, figs.1,4,9; Fensome et al., 1993, p.1095, figs.1-2
Paratype: Bailey, 1987
Locus typicus: British Geological Survey borehole 50/03 329, Lyme Bay, southern England
Stratum typicum: Sauzei Zone, Early Bajocian
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Durotrigia daveyi Bailey, 1987. The sutural features include low ridges usually surmounted by isolated projections and or denticulate crests which may be perforate. The spines or 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 appearing scabrate in transmitted light. The archeopyle is precingular formed from the loss of up to 5 plates. The most common type is 4P, with the first and sixth plates remaining attached. Excystment begins dorsally at the 3" and progresses ventrally in both directions. There are six cingular plates with often complex denticulate crests, which may be perforate and bear bifurcate spines. The sulcal plates are discernible. Note Diacanthum has a variable archeopyle (1-3P). Occisucysta and Tehamadinium have 2P archeopyles (2",3"). Liesbergia has a P or 2P archeopyle (3", 4") and has trabeculate parasutural ornamentation. Bailey (1987) did not give any details on the size of the specimens examined.
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Original diagnosis: Bailey, 1987, p.89
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.
Original description: Bailey, 1987, p.91
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 ([Bailey, 1987] 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.