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Callaiosphaeridium
From Williams et al., 2017:
[Callaiosphaeridium, Davey and Williams, 1966b, p. 103; Emendations: Duxbury, 1980, p. 113; Below, 1981, p. 27
nomencl. sr. synonym of Hexasphaera Clarke and Verdier, 1967, which has the same type species. tax. sr. synonym of Avellodinium Duxbury, 1977, according to Below, 1981. Lentin and Williams, 1981, retained Avellodinium as a separate genus.
Type species: originally as Hystrichosphaeridium asymmetricum, Deflandre and Courteville, 1939 (pl.4, fig.1)] ; Callaiosphaeridium asymmetricum, Davey and Williams, 1966
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Original description: [Davey and Williams, 1966]:
Diagnosis:
Chorate cysts with sub-spherical central body composed of two layers. Processes intratabular and of two types: (i) cingular processes large and tubular, open distally, and (ii) apical, precingular, postcingular and sulcal processes solid. Antapical processes absent. Reflected tabulation inferred from arrangement of processes is 1`(-2`), 6``, 6c, 5```, 1p, 0````, and 0-1s. Thickenings of periphragm join all except cingular processes. Archeopyle epitractal, suture just above cingular processes.
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Modified description:
Stover and Evitt 1978, p. 202:
Synopsis: Cysts skolochorate, acavate; body subspherical; paratabulation gonyaulacacean, indicated by parasutural ridges between gonal processes on epicyst and hypocyst and by intratabular paracingular processes; archeopyle, Type tAtP.
Description:
Shape: Body subspherical.
Wall relationships: Endophragm and periphragm appressed between processes, the periphragm forming processes and parasutural ridges; acavate.
Wall features: Parasutural ridges extend between bases of furcate gonal processes on epicyst and hypocyst. Paracingular intratabular processes tubular to trumpet shaped; gonal processes slender, generally solid with furcate tips.
Paratabulation: Indicated by intratabular processes and by parasutural ridges between gonal processes; gonyaulacacean, formula: 1-2`, 5-6``, 6c, 5```, 1````, and 1-3s.
Archeopyle: Combination epicystal, Type tAtP; operculum probably attached, but commonly separated; outline circular.
Paracingulum: Indicated by six intratabular processes.
Parasulcus: Location may be indicated by one or more small processes near the paracingulum.
Size: Intermediate to large.
Affinities:
Callaiosphaeridium differs from Spiniferites in having paracingular intratabular processes and an epicystal archeopyle, whereas Spiniferites has gonal or gonal and intergonal processes and a precingular archeopyle. Actinotheca, like Callaiosphaeridium, has an epicystal archeopyle, but its paracingulum is expressed by high thin septa rather than by intratabular processes.
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Emended descriptions:
Duxbury, 1980:
Diagnosis:
Spheroidal to ellipsoidal dinoflagellate cysts. The paracingulum has six tubular, distally open processes which are roughly equidistant from one another and which bear secondary, flexuous spines near their distal terminations. The epi- and hypocystal areas bear long gonal and parasutural
processes connected by parasutural crests of varying height. Such parasutural crests may be merely low surface ridges or may attain a height equal to that of the gonal processes. In the latter case, individual gonal and parasutural spines may be indistinguishable and the epi- and hypocystal areas may be considered to bear only high parasutural crests. The paratabulation is typically gonyaulacacean and the archeoplye is epicystal.
Affinities:
The main characteristic feature of Callaiosphaeridium is the presence of six tubular, paracingular processes. In other respects, it may be compared with Avellodinium Duxbury, 1977 and Heslertonia Sarjeant, 1966 emend. Duxbury, 1980. Avellodinium bears only gonal processes and has only very low parasutural crests. Heslertonia has only high, regular parasutural crests without tubular or Avellodinium-type processes. In the epi- and hypocystal areas, therefore, Callaiosphaeridium may combine the gonal process type of Avellodinium with the high parasutural crests typical of Heslertonia.
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Below, 1981: (Translation: LPP)
Diagnosis:
Chorate, bilayered cyst. Outline subspheroidal. Paratabulation gonyaulacoid 4`, 6``, 6c, 6```, 1pc, 1````, Xs. Low ridges or membranes follow the parasutures and connect gonal, solid or hollow, distally polyfurcate processes. Parasutural processes, taeniate in cross-section and distally furcate, may be developed. Paracingulum level, hexatabular with per paraplate one intratabular process, markedly tubular or similar to the gonal processes. Parasulcus subdivided or as an inarticulate broad zone. Combination archaeopyle (AP).
[Callaiosphaeridium, Davey and Williams, 1966b, p. 103; Emendations: Duxbury, 1980, p. 113; Below, 1981, p. 27
nomencl. sr. synonym of Hexasphaera Clarke and Verdier, 1967, which has the same type species. tax. sr. synonym of Avellodinium Duxbury, 1977, according to Below, 1981. Lentin and Williams, 1981, retained Avellodinium as a separate genus.
Type species: originally as Hystrichosphaeridium asymmetricum, Deflandre and Courteville, 1939 (pl.4, fig.1)] ; Callaiosphaeridium asymmetricum, Davey and Williams, 1966
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Davey and Williams, 1966]:
Diagnosis:
Chorate cysts with sub-spherical central body composed of two layers. Processes intratabular and of two types: (i) cingular processes large and tubular, open distally, and (ii) apical, precingular, postcingular and sulcal processes solid. Antapical processes absent. Reflected tabulation inferred from arrangement of processes is 1`(-2`), 6``, 6c, 5```, 1p, 0````, and 0-1s. Thickenings of periphragm join all except cingular processes. Archeopyle epitractal, suture just above cingular processes.
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Modified description:
Stover and Evitt 1978, p. 202:
Synopsis: Cysts skolochorate, acavate; body subspherical; paratabulation gonyaulacacean, indicated by parasutural ridges between gonal processes on epicyst and hypocyst and by intratabular paracingular processes; archeopyle, Type tAtP.
Description:
Shape: Body subspherical.
Wall relationships: Endophragm and periphragm appressed between processes, the periphragm forming processes and parasutural ridges; acavate.
Wall features: Parasutural ridges extend between bases of furcate gonal processes on epicyst and hypocyst. Paracingular intratabular processes tubular to trumpet shaped; gonal processes slender, generally solid with furcate tips.
Paratabulation: Indicated by intratabular processes and by parasutural ridges between gonal processes; gonyaulacacean, formula: 1-2`, 5-6``, 6c, 5```, 1````, and 1-3s.
Archeopyle: Combination epicystal, Type tAtP; operculum probably attached, but commonly separated; outline circular.
Paracingulum: Indicated by six intratabular processes.
Parasulcus: Location may be indicated by one or more small processes near the paracingulum.
Size: Intermediate to large.
Affinities:
Callaiosphaeridium differs from Spiniferites in having paracingular intratabular processes and an epicystal archeopyle, whereas Spiniferites has gonal or gonal and intergonal processes and a precingular archeopyle. Actinotheca, like Callaiosphaeridium, has an epicystal archeopyle, but its paracingulum is expressed by high thin septa rather than by intratabular processes.
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Emended descriptions:
Duxbury, 1980:
Diagnosis:
Spheroidal to ellipsoidal dinoflagellate cysts. The paracingulum has six tubular, distally open processes which are roughly equidistant from one another and which bear secondary, flexuous spines near their distal terminations. The epi- and hypocystal areas bear long gonal and parasutural
processes connected by parasutural crests of varying height. Such parasutural crests may be merely low surface ridges or may attain a height equal to that of the gonal processes. In the latter case, individual gonal and parasutural spines may be indistinguishable and the epi- and hypocystal areas may be considered to bear only high parasutural crests. The paratabulation is typically gonyaulacacean and the archeoplye is epicystal.
Affinities:
The main characteristic feature of Callaiosphaeridium is the presence of six tubular, paracingular processes. In other respects, it may be compared with Avellodinium Duxbury, 1977 and Heslertonia Sarjeant, 1966 emend. Duxbury, 1980. Avellodinium bears only gonal processes and has only very low parasutural crests. Heslertonia has only high, regular parasutural crests without tubular or Avellodinium-type processes. In the epi- and hypocystal areas, therefore, Callaiosphaeridium may combine the gonal process type of Avellodinium with the high parasutural crests typical of Heslertonia.
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Below, 1981: (Translation: LPP)
Diagnosis:
Chorate, bilayered cyst. Outline subspheroidal. Paratabulation gonyaulacoid 4`, 6``, 6c, 6```, 1pc, 1````, Xs. Low ridges or membranes follow the parasutures and connect gonal, solid or hollow, distally polyfurcate processes. Parasutural processes, taeniate in cross-section and distally furcate, may be developed. Paracingulum level, hexatabular with per paraplate one intratabular process, markedly tubular or similar to the gonal processes. Parasulcus subdivided or as an inarticulate broad zone. Combination archaeopyle (AP).