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Daveya
From Williams et al., 2017:
[Daveya, Monteil, 1996, p. 40-41
Type species: Daveya boresphaera, Monteil, 1996 (pl.1, figs.1–9; pl.2, figs.1–9)]
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Original description: [Monteil, 1996]:
Synopsis:
Cysts proximate to proximochorate, typically spherical, with a very short apical horn; thick and spongious, undifferentiated autophragm, ornamented with tubercles or spines; paratabulation gonyaulacacean, indicated by low to high parasutural septa, formula: 2pr, Oa, 4`, 6``, 6c, 6```, 1p, 1````, ?ras, 2 fpi; archeopyle precingular, type P3``, operculum typically adherent.
Description:
Shape: Typically spherical, with a very short apical horn, formed by linking of intratabular ornamentation and preapical/apical parasutures (Pl. 5, fig. 8, 9; Pl. 7, fig. 7-9; Pl. 8, fig. 7).
Wall relationships: Undifferentiated autophragm, thick and spongious; two appressed wall layers, pedium and luxuria, detectable using SEM (Pl. 8, fig. 6).
Wall features: Low parasutural septa (Pl. 7, fig. 7-10), rows of tubercles, bacula or pila (Pl. 3, fig. 1-9), or high parasutural septa proximally perforated and surmounted by long spines (Pl. 6, fig. 10-12; Pl. 8, fig. 2; Fig. 4); intratabular ornamentation tuberculate, baculate, pilate or echinate, with relief elements isolated (Pl. 6, fig. 4, 5) or distally linked (Pl. 3, fig. 2-5; Pl. 5, fig. 2).
Archeopyle: Precingular type P3..; operculum typically adherent.
Paratabulation: Clearly expressed by parasutural features; gonyaulacacean, formula: 2pr, Oa, 4`, 6``, 6c, 6```, 1p, 1````; ?ras, 2 fpi (Fig. 2, 3). Peculiarities: 4`/1` apical parasuture very clearly marked (Pl. 1, fig. 1, 2; Pl. 2, fig. 1, 2; Pl. 4, fig. 1-7; Pl. 5, fig. 7-9; Pl. 7, fig. 9, 10); paraplate apical 4` in contact with the anterior extremity (as border) of parasulcus (A/ai-arrangement of Helenes, 1986; Pl. 7, fig. 2); paraplates 1``` very long, narrow, and completely delineated by parasutures, 2``` large, 1p small and very posteriorly situated (Pl. 1, fig. 1, 2; Pl. 2, fig. 1, 2; Pl. 5, fig. 5-6; Pl. 6, fig. 1-3, 10-11; Pl. 8, fig. 5); paraplate 4``` asymmetrical (Pl. 8, fig. 1).
Paracingulum: Indicated by six rectangular transversely elongate paraplates; laevorotatory.
Parasulcus: Indicated by bordering parasutural features and central depression, slightly sigmoidal; subdivision not discernible, except for the questionable ras (Pl. 8, fig. 5); flagellar pore imprint marked by two deeper depressions (Pl. 1, fig. 4; Pl. 2, fig. 4; Pl. 8, fig. 5), interpreted as the anterior and posterior pore imprints (afpi and pfpi); S-type ventral organization (Evitt, 1985) with A/ai-arrangement.
Size: Small to intermediate, about 45 µm to 50 µm in diameter.
Remarks:
The gonyaulacacean paratabulation pattern with S-type ventral organisation exhibited by Daveya gen. nov., dictates its inclusion in the Gonyaulacoideae subfamily (Fensome et al., 1993, p. 91-94). The Leptodinioideae and Cribroperidinioideae subfamilies are characterised by an L-type ventral organisation.
Affinities:
Daveya gen. nov. differs from Gonyaulacysta Deflandre 1964 emend. Sarjeant 1982 in having a thick, spongious, undifferentiated autophragm and one typically adherent operculum, rather than two wall layers (bicavate to variously cavate) with a free operculum.
[Daveya, Monteil, 1996, p. 40-41
Type species: Daveya boresphaera, Monteil, 1996 (pl.1, figs.1–9; pl.2, figs.1–9)]
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Original description: [Monteil, 1996]:
Synopsis:
Cysts proximate to proximochorate, typically spherical, with a very short apical horn; thick and spongious, undifferentiated autophragm, ornamented with tubercles or spines; paratabulation gonyaulacacean, indicated by low to high parasutural septa, formula: 2pr, Oa, 4`, 6``, 6c, 6```, 1p, 1````, ?ras, 2 fpi; archeopyle precingular, type P3``, operculum typically adherent.
Description:
Shape: Typically spherical, with a very short apical horn, formed by linking of intratabular ornamentation and preapical/apical parasutures (Pl. 5, fig. 8, 9; Pl. 7, fig. 7-9; Pl. 8, fig. 7).
Wall relationships: Undifferentiated autophragm, thick and spongious; two appressed wall layers, pedium and luxuria, detectable using SEM (Pl. 8, fig. 6).
Wall features: Low parasutural septa (Pl. 7, fig. 7-10), rows of tubercles, bacula or pila (Pl. 3, fig. 1-9), or high parasutural septa proximally perforated and surmounted by long spines (Pl. 6, fig. 10-12; Pl. 8, fig. 2; Fig. 4); intratabular ornamentation tuberculate, baculate, pilate or echinate, with relief elements isolated (Pl. 6, fig. 4, 5) or distally linked (Pl. 3, fig. 2-5; Pl. 5, fig. 2).
Archeopyle: Precingular type P3..; operculum typically adherent.
Paratabulation: Clearly expressed by parasutural features; gonyaulacacean, formula: 2pr, Oa, 4`, 6``, 6c, 6```, 1p, 1````; ?ras, 2 fpi (Fig. 2, 3). Peculiarities: 4`/1` apical parasuture very clearly marked (Pl. 1, fig. 1, 2; Pl. 2, fig. 1, 2; Pl. 4, fig. 1-7; Pl. 5, fig. 7-9; Pl. 7, fig. 9, 10); paraplate apical 4` in contact with the anterior extremity (as border) of parasulcus (A/ai-arrangement of Helenes, 1986; Pl. 7, fig. 2); paraplates 1``` very long, narrow, and completely delineated by parasutures, 2``` large, 1p small and very posteriorly situated (Pl. 1, fig. 1, 2; Pl. 2, fig. 1, 2; Pl. 5, fig. 5-6; Pl. 6, fig. 1-3, 10-11; Pl. 8, fig. 5); paraplate 4``` asymmetrical (Pl. 8, fig. 1).
Paracingulum: Indicated by six rectangular transversely elongate paraplates; laevorotatory.
Parasulcus: Indicated by bordering parasutural features and central depression, slightly sigmoidal; subdivision not discernible, except for the questionable ras (Pl. 8, fig. 5); flagellar pore imprint marked by two deeper depressions (Pl. 1, fig. 4; Pl. 2, fig. 4; Pl. 8, fig. 5), interpreted as the anterior and posterior pore imprints (afpi and pfpi); S-type ventral organization (Evitt, 1985) with A/ai-arrangement.
Size: Small to intermediate, about 45 µm to 50 µm in diameter.
Remarks:
The gonyaulacacean paratabulation pattern with S-type ventral organisation exhibited by Daveya gen. nov., dictates its inclusion in the Gonyaulacoideae subfamily (Fensome et al., 1993, p. 91-94). The Leptodinioideae and Cribroperidinioideae subfamilies are characterised by an L-type ventral organisation.
Affinities:
Daveya gen. nov. differs from Gonyaulacysta Deflandre 1964 emend. Sarjeant 1982 in having a thick, spongious, undifferentiated autophragm and one typically adherent operculum, rather than two wall layers (bicavate to variously cavate) with a free operculum.