Back
Paragonyaulacysta fenesepta
From Fensome et al., 2019:
Paragonyaulacysta? fenesepta Mantle, 2009a, p.47–49, pl.7, figs.1–9; text-fig.10. Holotype: Mantle, 2009a, pl.7, fig.1. Questionable assignment: Mantle (2009a, p.47). Age: Callovian–early Oxfordian.
---------------------------------------------------------------------------------------------------
Original description [Mantle, 2009a]:
Paragonyaulacysta? fenesepta sp. nov.
Plate 7, Figs 1-9; text-fig. 10
Diagnosis: Cysts proximate, paratabulate, acavate; with a broadly ovoidal to polygonal shape surmounted-by a short, hollow, apical horn. Cyst wall single-layered. Autophragm scabrate to granulate and densely folded. Paratabulation evident, although typically obscured by numerous folds. Paratabulation formula unclear. Fenestrate septa with undulate to denticulate margins are parasutural (commonly) and intratabular (occasionally). Archeopyle intercalary, type 2I.
Description: Cysts vary from ovoidal to polygonal, broadest at the cingulum, often markedly so, and tapering sharply to the apices. The short apical horn is typically triangular in outline and may be extended by an apiculate structure in the form of a small, blunt rod or spongeous bundle. The apical horn is typically not obscured by the folding that covers much of the cyst; some specimens apparently show 5 or more pre-apical paraplates (text-fig. 10B). Paratabulation elsewhere on the cyst is incomplete and largely obscured by folds or poor preservation. However, a relatively narrow paracingulum is commonly evidenced by 6-7 paracingular plates; further parasutures indicate the presence of apical, anterior intercalary, precingular, postcingular, posterior sulcal, posterior intercalary and antapical paraplates. The parasutures are indicated by thin septa 0.5-5 um high. The latter are most prominent around the antapex and vary in form from fenestrate to
irregularly perforate with undulose (commonly), denticulate, or vaginate distal margins. The septa may be
tu.t}9Y:!.d by simple slender spines at the gonal points, parricula;ly along the parlcingulum. T-o ,pirr",
with bifid tips are present near the antapex oT o.,. ipecime.r. The archeopyl" is firmed iirrorgh the lo'ss of
intercalary.paraplates, llt j!. archeopyle margin is rar.ely clearly dei"ed and appears r; be type 2I.
However, the loss of a third intercalary paraplate cannor be dismissed conclusively.-
Dimensions (25 specimens): Total length of cyst 62 (75) 92 1t.rrr;
maximum width of cyst 3g (4g) 57 pm; thickness of cyst wall
0.5 um
Paragonyaulacysta? fenesepta Mantle, 2009a, p.47–49, pl.7, figs.1–9; text-fig.10. Holotype: Mantle, 2009a, pl.7, fig.1. Questionable assignment: Mantle (2009a, p.47). Age: Callovian–early Oxfordian.
---------------------------------------------------------------------------------------------------
Original description [Mantle, 2009a]:
Paragonyaulacysta? fenesepta sp. nov.
Plate 7, Figs 1-9; text-fig. 10
Diagnosis: Cysts proximate, paratabulate, acavate; with a broadly ovoidal to polygonal shape surmounted-by a short, hollow, apical horn. Cyst wall single-layered. Autophragm scabrate to granulate and densely folded. Paratabulation evident, although typically obscured by numerous folds. Paratabulation formula unclear. Fenestrate septa with undulate to denticulate margins are parasutural (commonly) and intratabular (occasionally). Archeopyle intercalary, type 2I.
Description: Cysts vary from ovoidal to polygonal, broadest at the cingulum, often markedly so, and tapering sharply to the apices. The short apical horn is typically triangular in outline and may be extended by an apiculate structure in the form of a small, blunt rod or spongeous bundle. The apical horn is typically not obscured by the folding that covers much of the cyst; some specimens apparently show 5 or more pre-apical paraplates (text-fig. 10B). Paratabulation elsewhere on the cyst is incomplete and largely obscured by folds or poor preservation. However, a relatively narrow paracingulum is commonly evidenced by 6-7 paracingular plates; further parasutures indicate the presence of apical, anterior intercalary, precingular, postcingular, posterior sulcal, posterior intercalary and antapical paraplates. The parasutures are indicated by thin septa 0.5-5 um high. The latter are most prominent around the antapex and vary in form from fenestrate to
irregularly perforate with undulose (commonly), denticulate, or vaginate distal margins. The septa may be
tu.t}9Y:!.d by simple slender spines at the gonal points, parricula;ly along the parlcingulum. T-o ,pirr",
with bifid tips are present near the antapex oT o.,. ipecime.r. The archeopyl" is firmed iirrorgh the lo'ss of
intercalary.paraplates, llt j!. archeopyle margin is rar.ely clearly dei"ed and appears r; be type 2I.
However, the loss of a third intercalary paraplate cannor be dismissed conclusively.-
Dimensions (25 specimens): Total length of cyst 62 (75) 92 1t.rrr;
maximum width of cyst 3g (4g) 57 pm; thickness of cyst wall
0.5 um