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Gonyaulacysta polythyris
Gonyaulacysta polythyris Davey, 1979
Holotype: Davey, 1979, pl.3, figs.1-3; Jan du Chêne et al., 1986, pl .39, figs.8-9
Age: Albian
(Daveu, 1979):
Derivation of name: Greek, polys, many and thyris, window — with reference to the perforate crests.
Holotype: MPK 1661, DSDP Leg 48, Hole 400A, Sample 62-2, 41-43 cm. Albian, northern Bay of Biscay.
Diagnosis: An ovoid species of Gonyaulacysta having a subconical apical horn and strongly developed, perforate parasutural crests. The crests are smooth distally, and are perforated by many variously sized holes. The cyst wall is thin, smooth, and bears a moderate number of stout intratabular spines. A precingular archeopyle is typically developed.
Dimensions: Holotype: Endocyst length 54 µm, Endocyst wisth 42 µm, Height of crests up to 9 µm. Range: Endocyst length 54-56 µm, Endocyst width 42-44 µm, Height of crests 6-9 µm (maximum).
Description: The crestal perforations are often elongate, with the long axis perpendicular to the cyst wall and, when several are present close together, the crest has a barred appearance. The crests are highest in the gonal regions and particularly at the margins of the apical and antapical plates. The intratabular spines are strongly developed (up to 3 µm in height), solid, and tend to be rounded and not pointed distally.
Remarks: The combination of perforate crests and stout intratabular spines differentiates G. polythyris sp. nov. from all previously described species. The overall appearance of this species, however, indicates that it belongs to the G. helicoidea lineage.
Holotype: Davey, 1979, pl.3, figs.1-3; Jan du Chêne et al., 1986, pl .39, figs.8-9
Age: Albian
(Daveu, 1979):
Derivation of name: Greek, polys, many and thyris, window — with reference to the perforate crests.
Holotype: MPK 1661, DSDP Leg 48, Hole 400A, Sample 62-2, 41-43 cm. Albian, northern Bay of Biscay.
Diagnosis: An ovoid species of Gonyaulacysta having a subconical apical horn and strongly developed, perforate parasutural crests. The crests are smooth distally, and are perforated by many variously sized holes. The cyst wall is thin, smooth, and bears a moderate number of stout intratabular spines. A precingular archeopyle is typically developed.
Dimensions: Holotype: Endocyst length 54 µm, Endocyst wisth 42 µm, Height of crests up to 9 µm. Range: Endocyst length 54-56 µm, Endocyst width 42-44 µm, Height of crests 6-9 µm (maximum).
Description: The crestal perforations are often elongate, with the long axis perpendicular to the cyst wall and, when several are present close together, the crest has a barred appearance. The crests are highest in the gonal regions and particularly at the margins of the apical and antapical plates. The intratabular spines are strongly developed (up to 3 µm in height), solid, and tend to be rounded and not pointed distally.
Remarks: The combination of perforate crests and stout intratabular spines differentiates G. polythyris sp. nov. from all previously described species. The overall appearance of this species, however, indicates that it belongs to the G. helicoidea lineage.