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Occisucysta balios

Occisucysta balios Gitmez, 1970; emend Jan du Chene et al., 1986

Holotype: Gitmez, 1970, pl.5, figs.1-2, text-fig.16, Jan du Chene et al., 1986(a), pl.77, figs.1-3; Jan du Chene et al., 1986(b), pl.1, figs.1-3
Locus typicus: Villerville, Normandy, France
Stratum typicum: Early Kimmeridgian
Translation Jan du Chene et al., 1986: LPP

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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.

Occisucysta balios Gitmez, 1970, emend. Jan du Chêne et al., 1986b. According to Jan du Chêne et al. (1986b, p.16), Occisucysta balios is a proximate subspherical to polyhedral cyst with a short apical horn. The paratabulation is 2pr, 4', 6", 6c, 5s, 6"’, 1p, 1"”. The parasutural septa are irregularly perforate and distally denticulate. The periphragm is tuberculate or verrucate. The endophragm is granulate and vacuolate. The archeopyle is formed from the loss of plates 2" and 3". The operculum is compound and free. Size: cyst length 48-68 µm, width 44-70 µm, holotype: cyst length 60 µm, width 60 µm, central body 50 x 55 µm, length of apical horn 8 µm.
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Original description: Gitmez, 1970, p. 267-268
Diagnosis: Occisucysta having a subspherical shell terminating in a strong, thick apical horn. Antapex rounded, dome-shaped. Tabulation: 4', 1a, 6'', 6c, 7''', 1p, 1pv, 1''''. The crests on the sutures are denticulate and fenestrate. Cingulum strongly helicoid, laevorotatory. Sulcus mainly confined to the epitract. Surface of the shell granular and sparsely tuberculate.
Dimensions: holotype: overall length 60 Ám, breadth 60 Ám; shell length 50 Ám, breadth 55 Ám; horn length 8 Ám, breadth 6 Ám.

Emended diagnosis: Jan du Chene et al., 1986b, p. 16
Proximate, subspherical to polyhedrical cyst, bearing a short apical horn, formed by the periphragm only. The gonyaulacoid paratabulation 2pr, 4', 6'', 6c, 5s, 6''', 1p, 1'''' is indicated by irregularly fenestrate parasutural septa, the crests ornamented with spines. The periphragm is thin, ornamented with tubercula which are more or less regularly dispersed on the intratabular areas. The endophragm is granular to vacuolar; it is thicker than the periphragm. The paracingulum is slightly laevorotatory, interrupted midventrally by the parasulcus. The archaeopyle is precingular, formed by the loss of paraplates 2'' and 3''. The operculum is composite and free.
Description: Proximate, cornucavate, probably partly suturocavate, subspherical to polyhedrical cyst, bearing a short, massive apical horn, formed by the periphragm only. The horn emerges from the body without marking an angle, where the periphragm is detached from the endophragm. The latter is granular or vacuolar, and clearly thicker than the periphragm. The gonyaulacoid paratabulation (2pr, 4', 6'', 6c, 5s, 6''', 1p, 1'''') is indicated by parasutural septa, the crests ornamented with thin, pointed spines. The paracingular septa are clearly higher and their crests are more strongly denticulate than those delimiting the other paraplates. The periphragm is ornamented with tubercula or spines which are more or less regularly dispersed on the intratabular areas. The paracingulum is slightly laevorotatory. The parasulcus is composed of 5 sulcal paraplates, generally well-defined. The position of the flagellar pores can be observed on the holotype. The archaeopyle is precingular, formed by the loss of paraplates 2'' and 3''. The operculum is composite and free.

Affinities:
Jan du Chene et al., 1986b, p. 16
O. balios differs from O. tentoria and O. duxburyi in its smaller size and its less well-pronounced apical horn.
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