Back
Gelatia
From Williams et al., 2017:
[Gelatia, Bujak, 1984, p. 185
Type species: Gelatia inflata, Bujak, 1984 (pl.1, fig.16)]
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Bujak, 1984]:
Diagnosis:
Endocyst spherical to ovoidal, small relative to pericyst, in contact with pericyst dorsally. Pericyst ovoidal, typically compressed in polar direction, with large opening present over most of dorsal epicyst that may correspond to plate 3".
Tabulation in the form of low sutural crests present or absent on endophragm and periphragm.
Archeopyle precingular, probably representing plate 3``.
Discussion:
The orientation and archaeopyle type described in the above diagnosis are based on the interpreted tabulation shown in text-fig. 2. This tabulation pattern is commonly present on specimens of the type species, G. inflata, but always appears to be incomplete. The plate designations shown are therefore tentative, but are consistent with gonyaulacacean plate patterns known from other Cenozoic cysts, such as Impagidinium Stover and Evitt.
Affinities:
Gelatia is similar to Thalassiphora Eisenack and Gocht in possessing a precingular archaeopyle and in having a pericyst that is much larger than the endocyst. Thalassiphora differs in always being dorso-ventrally compressed and in lacking the large dorsoventral opening present in Gelatia.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Modified description:
Stover and Williams, 1987, p. 101:
Synopsis:
Cysts proximate, camocavate, compressed apically-antapically, pericyst outline subcircular to elliptical; endocyst much smaller than pericyst; latter with large dorsal epicystal opening, periphragm in contact with endophragm dorsally, separated elsewhere; partial paratabulation, when indicated, depicted by low parasutural features; archeopyle precingular, probably type P.
Description:
Shape: Compressed apically-antapically, pericyst outline subcircular to elliptical.
Wall relationships: Cysts camocavate, ellipsoidal endocyst small, relative to pericyst, periphragm contacts endocyst dorsally, narrowly to widely
separated elsewhere.
Wall features: Pericyst with large dorsal epicystal opening and may have low, parasutural markings on hypocyst.
Archeopyle: Precingular, probably type P, (3"), operculum free.
Paratabulation: Apparently indicated on hypocyst only by parasutural features; seemingly gonyaulacacean, formula: 6```,1p, 1````,?2s.
Paracingulum: Not indicated.
Parasulcus: Posterior position expressed by posterior sulcal paraplate; other indications vague or lacking.
Size: Intermediate, pericyst about 50 µm to 75 µm.
Affinities:
Gelatia differs from Thalassiphora Eisenack and Gocht 1960 emended Benedek and Gocht 1981 in having a large dorsal epicystal opening and in being compressed apically-antapically. In contrast, the large opening in Thalassiphora is midventral, and specimens are not compressed apically- antapically. Gelatia differs from Invertocysta Edwards 1984 in having the periphragm and endocyst in contact dorsally rather than ventrally. Also in Invertocysta the paratabulation, when expressed, is indicated on the epicyst and hypocyst, rather than on just the latter.
[Gelatia, Bujak, 1984, p. 185
Type species: Gelatia inflata, Bujak, 1984 (pl.1, fig.16)]
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Bujak, 1984]:
Diagnosis:
Endocyst spherical to ovoidal, small relative to pericyst, in contact with pericyst dorsally. Pericyst ovoidal, typically compressed in polar direction, with large opening present over most of dorsal epicyst that may correspond to plate 3".
Tabulation in the form of low sutural crests present or absent on endophragm and periphragm.
Archeopyle precingular, probably representing plate 3``.
Discussion:
The orientation and archaeopyle type described in the above diagnosis are based on the interpreted tabulation shown in text-fig. 2. This tabulation pattern is commonly present on specimens of the type species, G. inflata, but always appears to be incomplete. The plate designations shown are therefore tentative, but are consistent with gonyaulacacean plate patterns known from other Cenozoic cysts, such as Impagidinium Stover and Evitt.
Affinities:
Gelatia is similar to Thalassiphora Eisenack and Gocht in possessing a precingular archaeopyle and in having a pericyst that is much larger than the endocyst. Thalassiphora differs in always being dorso-ventrally compressed and in lacking the large dorsoventral opening present in Gelatia.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Modified description:
Stover and Williams, 1987, p. 101:
Synopsis:
Cysts proximate, camocavate, compressed apically-antapically, pericyst outline subcircular to elliptical; endocyst much smaller than pericyst; latter with large dorsal epicystal opening, periphragm in contact with endophragm dorsally, separated elsewhere; partial paratabulation, when indicated, depicted by low parasutural features; archeopyle precingular, probably type P.
Description:
Shape: Compressed apically-antapically, pericyst outline subcircular to elliptical.
Wall relationships: Cysts camocavate, ellipsoidal endocyst small, relative to pericyst, periphragm contacts endocyst dorsally, narrowly to widely
separated elsewhere.
Wall features: Pericyst with large dorsal epicystal opening and may have low, parasutural markings on hypocyst.
Archeopyle: Precingular, probably type P, (3"), operculum free.
Paratabulation: Apparently indicated on hypocyst only by parasutural features; seemingly gonyaulacacean, formula: 6```,1p, 1````,?2s.
Paracingulum: Not indicated.
Parasulcus: Posterior position expressed by posterior sulcal paraplate; other indications vague or lacking.
Size: Intermediate, pericyst about 50 µm to 75 µm.
Affinities:
Gelatia differs from Thalassiphora Eisenack and Gocht 1960 emended Benedek and Gocht 1981 in having a large dorsal epicystal opening and in being compressed apically-antapically. In contrast, the large opening in Thalassiphora is midventral, and specimens are not compressed apically- antapically. Gelatia differs from Invertocysta Edwards 1984 in having the periphragm and endocyst in contact dorsally rather than ventrally. Also in Invertocysta the paratabulation, when expressed, is indicated on the epicyst and hypocyst, rather than on just the latter.