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Occisucysta monoheuriskos
Occisucysta? monoheuriskos Gitmez and Sarjeant, 1972; emend. Jan du Chêne et al., 1986
Originally Occisucysta, subsequently (and now) Occisucysta?.
At the time of the emendation, Jan du Chêne et al., 1986(b), questionably included this species in Occisucysta.
Holotype: Gitmez and Sarjeant, 1972, pl.7, figs.10-11, text-fig.21; Jan du Chêne et al., 1986(a), pl.77, figs.8-9; Jan du Chêne et al., 1986(b), pl.1, figs. 8-11
Paratype: Gitmez and Sarjeant, 1972
Locus typicus: Eathie Haven, South Cromarty, Scottland
Stratum typicum: Early Kimmeridgian
Translation Courtinat, 1989: LPP
Original diagnosis: Gitmez and Sarjeant, 1972, p.221
A species of Occisucysta with a globular cyst. Tabulation: 4", 6"", 7c, 7""", 1p, 1pv, 1"""", 2s. The epitract and hypotract are almost equal in size, seperated by the only slightly spiral, laevorotatory cingulum. The sulcus is broad and short, stretching from about mid-point on the epitract to about mid-point of the hypotract. The surface is finely granular and sparsely tuberculate. Sutures are in the form of spine rows; the spines are distally closed, oblate or bifid, generally simple, but the spines near to the apical horn are connected distally and thus appear more complicated. Short spines surround the distal end of the apicaI horn like a corona. A two-plate precingular archaeopyle is typically present, forming by loss of plates 2" and 3".
Dimensions: Holotype: overall length 70 µm, breadth 65 µm, horn length 10 µm; length of the sutural spines 5 µm, length of the spines surrounding the apical horn 3 µm.
Original description: Gitmez and Sarjeant, 1972, p.222
The cyst wall is relatively thick, c.1.5 µm. The cylindrical horn rises from the top of the dome-shaped epitract and is formed by two of the four apical plates 1" and 2". Plate 1" is elongate and broad, corresponding in position to the anterior prolongation of the sulcus. The other three apical plates are relatively large and of more or less equal size. The six precingular plates, together with the apical plates, make up the epitract; no intercalary plates are present. Except for plate 6"" which is narrow- and elongate, the precingular plates are quite large; plates 2" and 3" are lost in archaeopyle formation. The cingulum is occupied by 7 plates of variable size, the first and last (1c and 7c) being small. The ends of the cingulum are widely separated by a very broad sulcus, which widens further in its posterior portion. Two small plates are developed in the mid-portion of the sulcus.
The hypotract is hemi-spherical. The first postcingular plate (1""") is small, quadrate and placed in the flank of the sulcus. Plate 2""" is roughly triangular, and, because of the presence of the intercalary plate (1p), is reduced in size. Plates 3""" and 5""" are very large. Plate 6""" is narrow and elongate; plate 7""" is small. The single, convex antapical plate (1"""") is quite large. Two intercalary plates, 1p and 1pv, together form a crescent shape; 1pv separates the sulcus from the antapex.
Supplemental description: Courtinat, 1989, p.199: Occisucysta cf. monoheurikos
Cyst formed by an endophragm and periphragm, closely appressed except in the apical region where the periphragm is separated from the endophragm to form a short horn. The proximate cyst is ornamented with small scattered conical spines and hollow tuberculae in intratabular position. The wall, apart from its ornaments, is densely and delicately granular. The crests of the septa are spinous, except for the adcingular crests which are erymnate (fence-like). The cingular septa are irregularly developed; the anterior one is less high than the posterior one.
The archaeopyle is formed by the precingular paraplates 2 and 3 following the Kofoid notation and 3 and 4 following the Taylor-Evitt notation. The operculum is detached immediately above the anterior adcingular septum, contrary to O. balios, where this septum is detached with the operculum. The paratabulation is of gonyaulacacean type, without an anterior intercalary paraplate.
Remark: The ornamentation and crest type do not allow a good distinction of O. balios and O. cf monoheuriskos. But the ornamentation of the intratabular areas is a good criterium. Additionally, the heart-shaped fenestrations in the posterior adcingular septum of O. balios are absent in O. cf. monoheuriskos. O. cf. monoheuriskos has not been attributed to O. monoheuriskos, because the paratabulation is not the same as that cited in the original diagnosis.
Originally Occisucysta, subsequently (and now) Occisucysta?.
At the time of the emendation, Jan du Chêne et al., 1986(b), questionably included this species in Occisucysta.
Holotype: Gitmez and Sarjeant, 1972, pl.7, figs.10-11, text-fig.21; Jan du Chêne et al., 1986(a), pl.77, figs.8-9; Jan du Chêne et al., 1986(b), pl.1, figs. 8-11
Paratype: Gitmez and Sarjeant, 1972
Locus typicus: Eathie Haven, South Cromarty, Scottland
Stratum typicum: Early Kimmeridgian
Translation Courtinat, 1989: LPP
Original diagnosis: Gitmez and Sarjeant, 1972, p.221
A species of Occisucysta with a globular cyst. Tabulation: 4", 6"", 7c, 7""", 1p, 1pv, 1"""", 2s. The epitract and hypotract are almost equal in size, seperated by the only slightly spiral, laevorotatory cingulum. The sulcus is broad and short, stretching from about mid-point on the epitract to about mid-point of the hypotract. The surface is finely granular and sparsely tuberculate. Sutures are in the form of spine rows; the spines are distally closed, oblate or bifid, generally simple, but the spines near to the apical horn are connected distally and thus appear more complicated. Short spines surround the distal end of the apicaI horn like a corona. A two-plate precingular archaeopyle is typically present, forming by loss of plates 2" and 3".
Dimensions: Holotype: overall length 70 µm, breadth 65 µm, horn length 10 µm; length of the sutural spines 5 µm, length of the spines surrounding the apical horn 3 µm.
Original description: Gitmez and Sarjeant, 1972, p.222
The cyst wall is relatively thick, c.1.5 µm. The cylindrical horn rises from the top of the dome-shaped epitract and is formed by two of the four apical plates 1" and 2". Plate 1" is elongate and broad, corresponding in position to the anterior prolongation of the sulcus. The other three apical plates are relatively large and of more or less equal size. The six precingular plates, together with the apical plates, make up the epitract; no intercalary plates are present. Except for plate 6"" which is narrow- and elongate, the precingular plates are quite large; plates 2" and 3" are lost in archaeopyle formation. The cingulum is occupied by 7 plates of variable size, the first and last (1c and 7c) being small. The ends of the cingulum are widely separated by a very broad sulcus, which widens further in its posterior portion. Two small plates are developed in the mid-portion of the sulcus.
The hypotract is hemi-spherical. The first postcingular plate (1""") is small, quadrate and placed in the flank of the sulcus. Plate 2""" is roughly triangular, and, because of the presence of the intercalary plate (1p), is reduced in size. Plates 3""" and 5""" are very large. Plate 6""" is narrow and elongate; plate 7""" is small. The single, convex antapical plate (1"""") is quite large. Two intercalary plates, 1p and 1pv, together form a crescent shape; 1pv separates the sulcus from the antapex.
Supplemental description: Courtinat, 1989, p.199: Occisucysta cf. monoheurikos
Cyst formed by an endophragm and periphragm, closely appressed except in the apical region where the periphragm is separated from the endophragm to form a short horn. The proximate cyst is ornamented with small scattered conical spines and hollow tuberculae in intratabular position. The wall, apart from its ornaments, is densely and delicately granular. The crests of the septa are spinous, except for the adcingular crests which are erymnate (fence-like). The cingular septa are irregularly developed; the anterior one is less high than the posterior one.
The archaeopyle is formed by the precingular paraplates 2 and 3 following the Kofoid notation and 3 and 4 following the Taylor-Evitt notation. The operculum is detached immediately above the anterior adcingular septum, contrary to O. balios, where this septum is detached with the operculum. The paratabulation is of gonyaulacacean type, without an anterior intercalary paraplate.
Remark: The ornamentation and crest type do not allow a good distinction of O. balios and O. cf monoheuriskos. But the ornamentation of the intratabular areas is a good criterium. Additionally, the heart-shaped fenestrations in the posterior adcingular septum of O. balios are absent in O. cf. monoheuriskos. O. cf. monoheuriskos has not been attributed to O. monoheuriskos, because the paratabulation is not the same as that cited in the original diagnosis.