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Paragonyaulacysta

From Williams et al., 2017:

[Paragonyaulacysta, Johnson and Hills, 1973, p. 207; Emendations: Dörhöfer and Davies, 1980, p. 31; Below, 1990, p. 59–60.

Type species: Paragonyaulacysta calloviensis, Johnson and Hills, 1973 (pl.2, fig.9)] ; emend. Dörhöfer and Davies, 1980

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Original description: [Johnson and Hills, 1973]:

Description:
Proximate cysts, ellipsoidal in outline, surmounted by a short, thin, apical horn. Tabulation: 2`, 2a, 6``, 6c, 6```, 1p, 1````. Cingulum broad, helicoid, displaced ventrally by 1x its width, sulcus extends onto epitract and abuts against plate 1`. Sutures in form of low ridges which, at junctions with cingulum, bear short spines; surface of cyst smooth. Intercalary archeopyle formed by loss of plates 1a and 2a.

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Modified description:

Stover and Evitt, 1978, p. 115-116:

Synopsis:
Cysts proximate, ellipsoidal, with an apical horn; paratabulation indicated by low parasutural ridges; autophragm smooth; archeopyle intercalary, Type 2I; archeopyle index >0.5.

Description:
Shape: Ellipsoidal with an apical horn.
Wall Relationships: Autophragm only.
Wall features: Parasutural ridges low and with short gonal spines along the paracingulum. Autophragm smooth.
Paratabulation: Indicated by parasutral ridges; formula: 2-4`, 2a, 6``, 6c, 6```, 1p, 1````. Apical horn, formed by two large paraplates and a small third paraplate, may be present at the tip of the horn.
Archeopyle: Intercalary, Type 2I; archeopyle index >0.5; operculum free.
Paracingulum: Indicated by six rectangular transversely elongate paraplates.
Parasulcus: Longitudinally elongate area between paraplates 1` and 1````, wider antapically than apically, and bordered by parasutural ridges.
Size: Small

Affinities:
Paragonyaulacysta differs from Pluriarvalium in lacking numerous preapical and posterior intercalary paraplates. It differs from Pareodinia in having paratabulation additional to that expressed by the archeopyle.

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Emended descriptions:


Dörhöfer and Davies, 1980:

Diagnosis:
Proximate dinoflagellate cyst with elongate ovoidal outline. Apical horn always present, antapex +/- rounded. Tabulation marked by pronounced sutural crests. Surface smooth, granulate, verrucate or finely reticulate. Tabulation 4`, 3a, 6``, 6c, 6```, 2p, 2pv, 1````, ?s; archaeopyle 3I(1-3).

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Below, 1990: (Translation: LPP)

Diagnosis:
Vesicle-/plate arrangement of the dinoflagellate amphiesma cop, pop, cap, 3`, 2a, 6``, 7c, 6```, 2````, as, FM, ls, rs, ps; 1` exsert with adelopore on the suture 1`/6``, 1a quadragonal, 2a hexagonal. Growth of thecal plates ?gonyaulacoid.
Zygote-cyst habit proximate, proximochorate, chorate, cavate, acavate, squat or stretched ovoidal, ovaloidal, ellipsoidal, polyhedrical, also with apical horn; wall consisting of pedium and luxuria; surface smooth, ornamented or subdivided into paraplates by limbate ornaments. Paratabulation formula NR PR/XPR/cop, pop, cap, NR`/3`, NRa/1a(arch), 2a(arch)/2a, NR``/6``, NRc/Xc/7c, NR```/6```, NR````/2````, NRs/Xs/as, ls, rs, ps; 1` exsert, often with porichnion on the parasuture 1`/6`; archaeopyle anterior intercalary, 1a+2a or just 1a; operculum solvate, opercular plates secate, general opecular formula 1a(s)+2a(s) or just 1a(s).

Affinities:
The in exterior habit identical genus Lacrymodinium Albert et al. possesses a pentagonal 1a and 2a, which means that the anterior margin of 3`` is linear, but that of 4`` is geniculate.


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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.

Paragonyaulacysta Johnson and Hills, 1973, emend. Dörhöfer and Davies, 1980, emend. Below, 1990. This genus was emended by Below (1990, p.59-60) as follows. Arrangement of plates on the dinoflagellate amphiesma cop, pop, cap, 3`, 2a, 6", 7c, 6``` , 2```` , as, FM, ls, rs, ps: 1` exsert with adelopore on 1"/6" suture, 1a quadragonal, 2a hexagonal; tegulation 4*, 2**, 4***, 2****, 7c, 4x, 4xx, 3xxx; growth of thecal plates gonyaulacoid. Zygotic cyst habit proximate, proximochorate, chorate, cavate, acavate, compressed to oblong ovoidal, ovaloidal, ellipsoidal, polyhedral, and with an apical horn; wall composed of pedium and luxuria; surface smooth, ornamented or divided into plates by finite or limbate ornament; areation formula NR PR/XPR/cop, pop, cap, NR` ?3`, Nra/1Aarch, 2aarch/2a, NR`` /6", Nrc/Xc/7c, NR``` /6"'' , NR```` /2```` ; Nrs/Xs/as, ls, rs, ps; 1` exsert, frequently with porichnion on 1`/6" finis; archeopyle anterior intercalary 1a + 2a or only 1a; operculum solvate, opercular pieces secate, general opercular formula 1as=2as or only 1as.
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