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Comparodinium cavum
Comparodinium? cavum, Davies, 1983
Davies, 1983, questionably included this species in Comparodinium.
Holotype: Davies, 1983, pl.2, figs.10-11
Locus typicus: Ellef Ringes Island, District of Franklin, Northwest Territories, Canada
Stratum typicum: Toarcian-Bajocian
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Original description: [Davies, 1983, p. 16]:
Diagnosis:
A membranate dinoflagellate cyst species with a highly refractive autocyst, ovoidal in shape. and a thin hyaline ectophragm; with bifurcate processes grouped in apical, antapical and cingular locations, and thus developing three ectocoels in separate locations.
Tabulation: ?5", 3-"?4a, 8", "?c, 8""", 5p, 2"""", "?s.
Archeopyle: 4A, 4+3I(1-3).
Description:
The bifurcate processes are 2-3 µm long. The cingular processes form a double row which encircles the cyst. On well preserved specimens a thin ectophragm covers the processes creating three ectocoels corresponding to the groups of processes.
The cingular ectocoel is widely separated from the polar ectocoels and occasionally may be reduced or faintly evident.
Tabulation is indistinct, formed by faint lines on the periphragm and by archeopyle sutures.
The archeopyle appears to be a disintegration type as defined by Dörhöfer and Davies (1980).
Accessory sutures are found among both the intercalary plates and the precingular plates. A long narrow sulcus is present.
Dimensions:
length - 31(35)37 µm; breadth - 22(27)29 µm.
Affinities:
Comparodinium includes species without cingular processes and ectocoels which are present, however. in ?C. cavum; therefore the placement of this species in Comparodinium is tentative. The polar arrangement of the processes, the occasional reduction of the cingular processes and the similarity in archeopyle formation and tabulation indicate strong affinities to Comparodinium. C. Iineatum possesses trabaculae and has close affinities to ?C. cavum. The possession of the polar ectocoels and the intercalary plates is similar to ?Gillinia sp. of Dodekova (1975); however, ?Gillinia s p. of Dodekova ( 1975) does not have supporting processes. Cleistosphaeridium does not have ectocoels nor the alignment of processes shown by this species. Chlamydophorella possesses an entire enveloping ectophragm.
Davies, 1983, questionably included this species in Comparodinium.
Holotype: Davies, 1983, pl.2, figs.10-11
Locus typicus: Ellef Ringes Island, District of Franklin, Northwest Territories, Canada
Stratum typicum: Toarcian-Bajocian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Davies, 1983, p. 16]:
Diagnosis:
A membranate dinoflagellate cyst species with a highly refractive autocyst, ovoidal in shape. and a thin hyaline ectophragm; with bifurcate processes grouped in apical, antapical and cingular locations, and thus developing three ectocoels in separate locations.
Tabulation: ?5", 3-"?4a, 8", "?c, 8""", 5p, 2"""", "?s.
Archeopyle: 4A, 4+3I(1-3).
Description:
The bifurcate processes are 2-3 µm long. The cingular processes form a double row which encircles the cyst. On well preserved specimens a thin ectophragm covers the processes creating three ectocoels corresponding to the groups of processes.
The cingular ectocoel is widely separated from the polar ectocoels and occasionally may be reduced or faintly evident.
Tabulation is indistinct, formed by faint lines on the periphragm and by archeopyle sutures.
The archeopyle appears to be a disintegration type as defined by Dörhöfer and Davies (1980).
Accessory sutures are found among both the intercalary plates and the precingular plates. A long narrow sulcus is present.
Dimensions:
length - 31(35)37 µm; breadth - 22(27)29 µm.
Affinities:
Comparodinium includes species without cingular processes and ectocoels which are present, however. in ?C. cavum; therefore the placement of this species in Comparodinium is tentative. The polar arrangement of the processes, the occasional reduction of the cingular processes and the similarity in archeopyle formation and tabulation indicate strong affinities to Comparodinium. C. Iineatum possesses trabaculae and has close affinities to ?C. cavum. The possession of the polar ectocoels and the intercalary plates is similar to ?Gillinia sp. of Dodekova (1975); however, ?Gillinia s p. of Dodekova ( 1975) does not have supporting processes. Cleistosphaeridium does not have ectocoels nor the alignment of processes shown by this species. Chlamydophorella possesses an entire enveloping ectophragm.