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Tanyosphaeridium paradoxum
Tanyosphaeridium paradoxum (Brosius, 1963) Gocht 1969
Now Distatodinium. Originally Hystrichosphaeridium, subsequently Tanyosphaeridium, thirdly Oligosphaeridium?, fourthly (and now) Distatodinium, fifthly Bipolaribucina.
Taxonomic junior synonym: Distatodinium craterum, according to Fensome et al. (2009, p.31).
Holotype: Brosius, 1963, pl.4, fig.6
Paratype: Brosius, 1963
Locus typicus: Stolzenbach borehole, S of Borken, Germany
Stratum typicum: Late Oligocene
Translation Brosius, 1963: LPP
Translation Gocht, 1969: Geological Survey of Canada
Original description: Brosius 1963, p. 41: Hystrichosphaeridium paradoxum
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.
Gocht, 1969, p.54,55:
Good specimens of this very delicate hyaline form were found from the Oligocene. All of Brosius" observations were confirmed. The elongate body bears branched processes which are exceptionally variable in number, arrangement, and shape. On some specimens, they are limited partly or completely to the polar regions; others have individual small appendages also on the middle of the body, and still others have processes distributed evenly over their entire body. From nine to more than twenty processes per individual were counted. The processes are hollow and have slender shafts with plain or markedly widened bases. They divide in the last third or quarter of their total length into long, acute spines, antlerlike branchings, or fine, short tines. Multiple branching occurs, as well as "processes on processes" and distal bridges between two appendages. The variation extends from unbranched, tubular shafts to deeply slit, bizarre formations. Cutaneous bridges or "sails" may connect the processes basally. Some specimens seem like malformations. It should be emphasized, however, that all extreme phenomena are limited to a minority of the specimens examined, and the variability of the processes normally remains within bounds; only their number is always variable.
As Brosius already observed, the pylome is formed by the detachment of a calotte near the polar region. This polar cap, which was never observed in isolation, is apparently quite small, since the polar processes (or some of them) are always still on the body. The pylome suture is usually irregular, so that in individual cases, especially with the fragile membranes of this taxon, it is not always easy to resolve whether an opening resulted from excystment or from injury. Probably the closest form to T. paradoxum is T. ellipticum (Cookson, 1965) from the Late Eocene of SE Australia. T. ellipticum has a larger number of processes (30-45), which are also thinner and less ramified. With extensions up to 230 µm and more, T. paradoxum is the largest "hystrichosphere" of the Meckelfeld Tertiary.
Occurrence: Middle Oligocene.
Now Distatodinium. Originally Hystrichosphaeridium, subsequently Tanyosphaeridium, thirdly Oligosphaeridium?, fourthly (and now) Distatodinium, fifthly Bipolaribucina.
Taxonomic junior synonym: Distatodinium craterum, according to Fensome et al. (2009, p.31).
Holotype: Brosius, 1963, pl.4, fig.6
Paratype: Brosius, 1963
Locus typicus: Stolzenbach borehole, S of Borken, Germany
Stratum typicum: Late Oligocene
Translation Brosius, 1963: LPP
Translation Gocht, 1969: Geological Survey of Canada
Original description: Brosius 1963, p. 41: Hystrichosphaeridium paradoxum
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.
Gocht, 1969, p.54,55:
Good specimens of this very delicate hyaline form were found from the Oligocene. All of Brosius" observations were confirmed. The elongate body bears branched processes which are exceptionally variable in number, arrangement, and shape. On some specimens, they are limited partly or completely to the polar regions; others have individual small appendages also on the middle of the body, and still others have processes distributed evenly over their entire body. From nine to more than twenty processes per individual were counted. The processes are hollow and have slender shafts with plain or markedly widened bases. They divide in the last third or quarter of their total length into long, acute spines, antlerlike branchings, or fine, short tines. Multiple branching occurs, as well as "processes on processes" and distal bridges between two appendages. The variation extends from unbranched, tubular shafts to deeply slit, bizarre formations. Cutaneous bridges or "sails" may connect the processes basally. Some specimens seem like malformations. It should be emphasized, however, that all extreme phenomena are limited to a minority of the specimens examined, and the variability of the processes normally remains within bounds; only their number is always variable.
As Brosius already observed, the pylome is formed by the detachment of a calotte near the polar region. This polar cap, which was never observed in isolation, is apparently quite small, since the polar processes (or some of them) are always still on the body. The pylome suture is usually irregular, so that in individual cases, especially with the fragile membranes of this taxon, it is not always easy to resolve whether an opening resulted from excystment or from injury. Probably the closest form to T. paradoxum is T. ellipticum (Cookson, 1965) from the Late Eocene of SE Australia. T. ellipticum has a larger number of processes (30-45), which are also thinner and less ramified. With extensions up to 230 µm and more, T. paradoxum is the largest "hystrichosphere" of the Meckelfeld Tertiary.
Occurrence: Middle Oligocene.