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Bipolaribucina paradoxa
Bipolaribucina paradoxa, (Brosius, 1963), Lentin and Williams, 1981
Now Distatodinium. Originally Hystrichosphaeridium, subsequently Tanyosphaeridium, thirdly Oligosphaeridium?, fourthly (and now) Distatodinium, fifthly Bipolaribucina.
Jiabo, 1978, failed to give a complete citation for the basionym, Hystrichosphaeridium paradoxum Brosius, 1963, when they intended to transfer this species to Bipolaribucina. Chen et al., 1988, retained this species in Distatodinium Eaton, 1976.
Taxonomic junior synonym: Distatodinium craterum, according to Fensome et al. (2009, p.31).
Holotype: Brosius, 1963, pl.4, fig.6
Age: Late Oligocene
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Original description as Hystrichosphaeridium paradoxum: [Brosius 1963, p. 41]:
Diagnosis:
The cigar-shaped oval body has a tender, smooth to finely granulate membrane.
The irregularly arranged hollow processes are connected to the body with a broadened base. They vary considerably in development and length. The principally occurring process-type broadens funnel-like distally. The outer rim bears several very long, whip-like and branched appendices. Additionally, single and branched tubes occur as well. Fused bases between two processes occur regularly. In most specimens a calotte is split off as a pylome at one of the narrow sides.
Dimensions:
Holotype: L:B without processes 58:27 µm, process length 26 µm. Mean L:B without processes 60:30 µm, processes 18-50 µm. 20 specimens.
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Supplemental description as Distatodinium paradoxum:
Eaton 1976, p. 265:
Description:
The cyst body has an oval or elongate outline and a smooth or finely granular surface.
The processes are typically slender, simple or branched, distally and proximally expanded, usually flattened and blade-like in cross section, occasionally tubular. Distally they are bifurcate or trifurcate with some secondary and tertiary branchlets at the extremities. The number of processes is about 20 and their distribution is similar to that of D. craterum. In addition to the alignment of the processes into rings around the cyst body, there is also some alignment into rows parallel to the long axis. Adjacent longitudinally aligned processes may be proximally united by membrane.
Archeopyle apical. One specimen (Pl.9,fig.6) shows partial detachment of the polar region. If this is interpreted as the apical zone, the operculum bears four processes, two of which are proximally united by membrane.
Dimensions:
Observed range: cyst body, length (with operculum): 46 µm; length (without operculum): 36-52 µm; breadth: 28-42 µm; length of processes up to 24 µm (n=6).
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Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Distatodinium paradoxum (Brosius, 1963) Eaton, 1976. According to Eaton (1976, p. 265), this species has typically slender processes, simple or branched, distally and proximally expanded, usually flattened and blade-like in cross-section. Distally they are bifurcate or trifurcate with some secondary and tertiary branchlets at the extremities. There are about 20 processes. There are 6 precingular and at least 5 postcingular. The processes are arranged in rings around the body and show some longitudinal alignment. The straight or curved lines marking the divergence of the processes from the cyst body are also proximally united by membranes.
Size: average length (without processes) 60 µm, width 30 µm, process length 18-50 µm.
Now Distatodinium. Originally Hystrichosphaeridium, subsequently Tanyosphaeridium, thirdly Oligosphaeridium?, fourthly (and now) Distatodinium, fifthly Bipolaribucina.
Jiabo, 1978, failed to give a complete citation for the basionym, Hystrichosphaeridium paradoxum Brosius, 1963, when they intended to transfer this species to Bipolaribucina. Chen et al., 1988, retained this species in Distatodinium Eaton, 1976.
Taxonomic junior synonym: Distatodinium craterum, according to Fensome et al. (2009, p.31).
Holotype: Brosius, 1963, pl.4, fig.6
Age: Late Oligocene
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description as Hystrichosphaeridium paradoxum: [Brosius 1963, p. 41]:
Diagnosis:
The cigar-shaped oval body has a tender, smooth to finely granulate membrane.
The irregularly arranged hollow processes are connected to the body with a broadened base. They vary considerably in development and length. The principally occurring process-type broadens funnel-like distally. The outer rim bears several very long, whip-like and branched appendices. Additionally, single and branched tubes occur as well. Fused bases between two processes occur regularly. In most specimens a calotte is split off as a pylome at one of the narrow sides.
Dimensions:
Holotype: L:B without processes 58:27 µm, process length 26 µm. Mean L:B without processes 60:30 µm, processes 18-50 µm. 20 specimens.
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Supplemental description as Distatodinium paradoxum:
Eaton 1976, p. 265:
Description:
The cyst body has an oval or elongate outline and a smooth or finely granular surface.
The processes are typically slender, simple or branched, distally and proximally expanded, usually flattened and blade-like in cross section, occasionally tubular. Distally they are bifurcate or trifurcate with some secondary and tertiary branchlets at the extremities. The number of processes is about 20 and their distribution is similar to that of D. craterum. In addition to the alignment of the processes into rings around the cyst body, there is also some alignment into rows parallel to the long axis. Adjacent longitudinally aligned processes may be proximally united by membrane.
Archeopyle apical. One specimen (Pl.9,fig.6) shows partial detachment of the polar region. If this is interpreted as the apical zone, the operculum bears four processes, two of which are proximally united by membrane.
Dimensions:
Observed range: cyst body, length (with operculum): 46 µm; length (without operculum): 36-52 µm; breadth: 28-42 µm; length of processes up to 24 µm (n=6).
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Distatodinium paradoxum (Brosius, 1963) Eaton, 1976. According to Eaton (1976, p. 265), this species has typically slender processes, simple or branched, distally and proximally expanded, usually flattened and blade-like in cross-section. Distally they are bifurcate or trifurcate with some secondary and tertiary branchlets at the extremities. There are about 20 processes. There are 6 precingular and at least 5 postcingular. The processes are arranged in rings around the body and show some longitudinal alignment. The straight or curved lines marking the divergence of the processes from the cyst body are also proximally united by membranes.
Size: average length (without processes) 60 µm, width 30 µm, process length 18-50 µm.