Back
Eodinia
From Williams et al., 2017:
[Eodinia, Eisenack, 1936, p. 73-74; Emendations: Gocht, 1975a, p. 27; Berger, 1986, p. 344
Type species: Eodinia pachytheca, Eisenack, 1936 (text-fig.1)] ; emend. Gocht, 1975
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Eisenack, 1936]: (Translation: Stover and Evitt, 1978, p. 207):
Description:
The shell of this species is made up of two parts, the epivalve and the hypovalve. The first is nearly hemispherical, flattened, with a short protruding horn; the latter is like the rounded base of a skittle, and higher than the epivalve.
The inner space is more oval and is not or only slightly protruding into the apical horn.
In completely undamaged specimens it is difficult to recognize a transverse furrow or a suture, but shells broken along the circular sutures are frequently found, the two parts still somewhat attached and more or less separated from each other. In others a fine trace already indicates this separation line. Separated halves are also common. The ring-shaped suture is completely circular; in optical cross section it appears sometimes as a fine v-shaped notch in the wall. It is in fact only a suture, not a true cingular band with its own plates. It encircles the shell at its point of greatest circumference. The longitudinal furrow is still more difficult to see. A shallow depression should be considered as such; this depression begins from the transverse furrow and extends approximately to half the height of the hypovalve. It is deepest in its middle. The thickness of the wall prevents its being visible in optical cross section in lateral view. In polar view it appears as a slight flexure of the otherwise circular cross section. The furrow does not extend into the epivalve.
The shell is relatively thick and completely without tabulation. It seems penetrated by numerous pores, which can be point- or line-shaped. It is not possible to decide if the apical horn is perforated by a fine pore, but it seems often to be the case.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Emended descriptions:
Gocht, 1975: (Translation: Stover and Evitt, 1978, p. 207):
Description:
Body polygonal to ovoidal with short step-like apical horn. Greatest thickness of body at lower margin of girdle. Girdle not divided, or rarely so, longitudinal furrow clearly divided. Longitudinal furrow formed out of the small 1``` plate, the elongate lp as well as six additional plates. Plate 2``` triangular; remaining postcingular and precingular plates trapeziform. Apical plates not clearly definable. Antapical plate somewhat quadrate. Tabulation: 4` (?), 6``, 6c (?), 6```, 1````, 1p; six in longitudinal furrow. Meridional and circumpolar sutures often or always accompanied by intercalary band-like, transversely striated zones. Ornamentation pattern of circular and net-like ridges present on rest of outer wall.
Strong endophragm and thinner periphragm connected by a system of irregular fibres or bundles of fibres.
Archeopyle cingular.
-----------------------------------
Berger, 1986:
Diagnosis:
Polygonal or ovoid body, with small apical horn. The widest part of the test is in the lower part of the paracingulum.
Paratabulation standard gonyaulacacean 4`, 1a, 6``, ?6c, 6```, 1p, 1````, 6s.
Parasutures often underlined by spines. Double wall with endophragma and periphragma joined by massive elements giving a mosaical aspect. Archeopyle epicystal.
Affinities:
Eodinia can be distinguished from Ctenidodinium and Korystocysta by the double wall connected by massive or fibrous elements and by the growth of the postcingular plates on both sides.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Modified descriptions:
Stover and Evitt, 1978, p. 207-208:
Synopsis:
Cysts proximate, ellipsoidal with short apical horn; autophragm and ectophragm connected by irregularly disposed fibrous rods; paratabulation typically indistinct, gonyaulacacean, indicated by parasutural bands; combination epicystal archeopyle, Type tAtPa.
Description:
Shape: Ellipsoidal with short apical horn.
Wall relationships: Autophragm and ectophragm separated; ectocoel occupied by ire. Irregularly distributed individual or groups of fibrous, rodlike projections that vary in width and extend between the walls.
Wall features: Parasutural bands, which may have low medial crests outlining paraplates. Ectophragm has system of reticulate ridges, which surround lumina or perforations.
Paratabulation: When discernible (see Comment below), indicated by parasutural features; gonyaulacacean, formula: ?4`, 6``, Xc-?6c, 6```, 1p, 1````, 6s.
Archeopyle: Combination, epicystal, Type tAtPa; operculum normally attached ventrally.
Paracingulum: Indicated generally by transverse parallel ridges; rarely subdivided.
Parasulcus: Shallow subdivided depression confined mainly to hypocyst.
Size: Intermediate to large.
Affinities:
The paratabulation, although clearly evident in SEM photomicrographs, is only vaguely discernible with light microscopy.
[Eodinia, Eisenack, 1936, p. 73-74; Emendations: Gocht, 1975a, p. 27; Berger, 1986, p. 344
Type species: Eodinia pachytheca, Eisenack, 1936 (text-fig.1)] ; emend. Gocht, 1975
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Eisenack, 1936]: (Translation: Stover and Evitt, 1978, p. 207):
Description:
The shell of this species is made up of two parts, the epivalve and the hypovalve. The first is nearly hemispherical, flattened, with a short protruding horn; the latter is like the rounded base of a skittle, and higher than the epivalve.
The inner space is more oval and is not or only slightly protruding into the apical horn.
In completely undamaged specimens it is difficult to recognize a transverse furrow or a suture, but shells broken along the circular sutures are frequently found, the two parts still somewhat attached and more or less separated from each other. In others a fine trace already indicates this separation line. Separated halves are also common. The ring-shaped suture is completely circular; in optical cross section it appears sometimes as a fine v-shaped notch in the wall. It is in fact only a suture, not a true cingular band with its own plates. It encircles the shell at its point of greatest circumference. The longitudinal furrow is still more difficult to see. A shallow depression should be considered as such; this depression begins from the transverse furrow and extends approximately to half the height of the hypovalve. It is deepest in its middle. The thickness of the wall prevents its being visible in optical cross section in lateral view. In polar view it appears as a slight flexure of the otherwise circular cross section. The furrow does not extend into the epivalve.
The shell is relatively thick and completely without tabulation. It seems penetrated by numerous pores, which can be point- or line-shaped. It is not possible to decide if the apical horn is perforated by a fine pore, but it seems often to be the case.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Emended descriptions:
Gocht, 1975: (Translation: Stover and Evitt, 1978, p. 207):
Description:
Body polygonal to ovoidal with short step-like apical horn. Greatest thickness of body at lower margin of girdle. Girdle not divided, or rarely so, longitudinal furrow clearly divided. Longitudinal furrow formed out of the small 1``` plate, the elongate lp as well as six additional plates. Plate 2``` triangular; remaining postcingular and precingular plates trapeziform. Apical plates not clearly definable. Antapical plate somewhat quadrate. Tabulation: 4` (?), 6``, 6c (?), 6```, 1````, 1p; six in longitudinal furrow. Meridional and circumpolar sutures often or always accompanied by intercalary band-like, transversely striated zones. Ornamentation pattern of circular and net-like ridges present on rest of outer wall.
Strong endophragm and thinner periphragm connected by a system of irregular fibres or bundles of fibres.
Archeopyle cingular.
-----------------------------------
Berger, 1986:
Diagnosis:
Polygonal or ovoid body, with small apical horn. The widest part of the test is in the lower part of the paracingulum.
Paratabulation standard gonyaulacacean 4`, 1a, 6``, ?6c, 6```, 1p, 1````, 6s.
Parasutures often underlined by spines. Double wall with endophragma and periphragma joined by massive elements giving a mosaical aspect. Archeopyle epicystal.
Affinities:
Eodinia can be distinguished from Ctenidodinium and Korystocysta by the double wall connected by massive or fibrous elements and by the growth of the postcingular plates on both sides.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Modified descriptions:
Stover and Evitt, 1978, p. 207-208:
Synopsis:
Cysts proximate, ellipsoidal with short apical horn; autophragm and ectophragm connected by irregularly disposed fibrous rods; paratabulation typically indistinct, gonyaulacacean, indicated by parasutural bands; combination epicystal archeopyle, Type tAtPa.
Description:
Shape: Ellipsoidal with short apical horn.
Wall relationships: Autophragm and ectophragm separated; ectocoel occupied by ire. Irregularly distributed individual or groups of fibrous, rodlike projections that vary in width and extend between the walls.
Wall features: Parasutural bands, which may have low medial crests outlining paraplates. Ectophragm has system of reticulate ridges, which surround lumina or perforations.
Paratabulation: When discernible (see Comment below), indicated by parasutural features; gonyaulacacean, formula: ?4`, 6``, Xc-?6c, 6```, 1p, 1````, 6s.
Archeopyle: Combination, epicystal, Type tAtPa; operculum normally attached ventrally.
Paracingulum: Indicated generally by transverse parallel ridges; rarely subdivided.
Parasulcus: Shallow subdivided depression confined mainly to hypocyst.
Size: Intermediate to large.
Affinities:
The paratabulation, although clearly evident in SEM photomicrographs, is only vaguely discernible with light microscopy.