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Cymososphaeridium sp. i of davey 1982b
Cymososphaeridium sp.1 of Davey 1982b
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Genus: Cymososphaeridium Davey, 1982
Type species: Cymososphaeridium validum Davey, 1982
Original diagnosis: Davey, 1982, p. 18
Shape: The body is spherical to subspherical in shape with minor dorso-ventral flattening.
Wall: The cyst wall is apparently two-layered, the two layers being closely appressed except where the periphragm alone forms the processes. The surface is smooth to scabrate.
Paratabulation: Parasutures not observed.
Processes: The solid, plate-centred processes vary in size with 1""" being particularly small. Paracingular processes are absent. The processes branch, usually medially or distally, to give rise to two to four main branches and these may give rise to further branches. The process formula is 4", 6"", 6""", lp, 1"""", lps.
Archaeopyle. An apical archaeopyle is developed by the detachment of the apical paraplates as a unit (Type (A)). The archaeopyle has a strongly zigzag margin.
Stover and Williams, 1987, p. 67
Synopsis: Cysts skolochorate, body subspherical, with 19 solid, branched, intratabular processes; cingular processes absent; paratabulation indicated by the apical type [4A] archeopyle and by the processes; formula: 4", 6", 0c, 6""",1p, 1"""" and 1ps; operculum free.
Modified description:
Shape: Body subspherical.
Wall relationships: Apparently two-layered; periphragm and endophragm appressed except where the periphragm forms the processes.
Wall features: Intratabular processes solid, medially to distally branched; primary branches may be further branched repeatedly. Cyst body smooth to scabrate.
Archeopyle: Apical, type [4A], principal archeopyle suture zigzag; operculum free.
Paratabulation: Indicated by archeopyle and by intratabular processes; formula: 4", 6", 0c, 6""", 1 p, 1"""" and ps.
Paracingulum: Indicated by the lack of processes in the equatorial area.
Parasulcus: Position indicated anteriorly by the sulcal notch and posteriorly by the posterior sulcal (ps) process; other sulcal paraplates are without processes.
Size: Intermediate; about 70 to 95 Ám.
Affinities:
Stover and Williams, 1987, p. 67: According to Davey (1982b, p. 18), the form of the processes in Cymososphaeridium is almost identical to that of Surculosphaeridium Davey et al., 1966, but the latter genus has cingular processes. The process formula of Cymososphaeridium is the same as for Oligosphaeridium Davey and Williams in Davey et al., 1966 emended Davey 1982 and for Stiphrosphaeridium Davey 1982. Oligosphaeridium has tubiform processes, however, whereas the processes on Stiphrosphaeridium have mostly solid stems and hollow, expanded fenestrate distal ends.
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Genus: Cymososphaeridium Davey, 1982
Type species: Cymososphaeridium validum Davey, 1982
Original diagnosis: Davey, 1982, p. 18
Shape: The body is spherical to subspherical in shape with minor dorso-ventral flattening.
Wall: The cyst wall is apparently two-layered, the two layers being closely appressed except where the periphragm alone forms the processes. The surface is smooth to scabrate.
Paratabulation: Parasutures not observed.
Processes: The solid, plate-centred processes vary in size with 1""" being particularly small. Paracingular processes are absent. The processes branch, usually medially or distally, to give rise to two to four main branches and these may give rise to further branches. The process formula is 4", 6"", 6""", lp, 1"""", lps.
Archaeopyle. An apical archaeopyle is developed by the detachment of the apical paraplates as a unit (Type (A)). The archaeopyle has a strongly zigzag margin.
Stover and Williams, 1987, p. 67
Synopsis: Cysts skolochorate, body subspherical, with 19 solid, branched, intratabular processes; cingular processes absent; paratabulation indicated by the apical type [4A] archeopyle and by the processes; formula: 4", 6", 0c, 6""",1p, 1"""" and 1ps; operculum free.
Modified description:
Shape: Body subspherical.
Wall relationships: Apparently two-layered; periphragm and endophragm appressed except where the periphragm forms the processes.
Wall features: Intratabular processes solid, medially to distally branched; primary branches may be further branched repeatedly. Cyst body smooth to scabrate.
Archeopyle: Apical, type [4A], principal archeopyle suture zigzag; operculum free.
Paratabulation: Indicated by archeopyle and by intratabular processes; formula: 4", 6", 0c, 6""", 1 p, 1"""" and ps.
Paracingulum: Indicated by the lack of processes in the equatorial area.
Parasulcus: Position indicated anteriorly by the sulcal notch and posteriorly by the posterior sulcal (ps) process; other sulcal paraplates are without processes.
Size: Intermediate; about 70 to 95 Ám.
Affinities:
Stover and Williams, 1987, p. 67: According to Davey (1982b, p. 18), the form of the processes in Cymososphaeridium is almost identical to that of Surculosphaeridium Davey et al., 1966, but the latter genus has cingular processes. The process formula of Cymososphaeridium is the same as for Oligosphaeridium Davey and Williams in Davey et al., 1966 emended Davey 1982 and for Stiphrosphaeridium Davey 1982. Oligosphaeridium has tubiform processes, however, whereas the processes on Stiphrosphaeridium have mostly solid stems and hollow, expanded fenestrate distal ends.