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Araneosphaera stephanophora
From Fensome et al., 2019:
Arenosphaera stephanophora (Benedek, 1972, p.30–31, pl.9, fig.6; text-fig.10) Benedek and Sarjeant, 1981, p.349–350.
Emendation: Benedek and Sarjeant, 1981, p.349–350, as Araneosphaera stephanophora. Holotype: Benedek, 1972,
pl.9, fig.6. Originally Hystrichosphaeridium, subsequently Hystrichosphaeridium?, thirdly (and now)
Araneosphaera. Age: Middle–Late Oligocene.
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Original description: [Benedek, 1972, p. 30-31] (translated from German):
Hystrichosphaeridium stephanophorum n. sp.
Derivio nominis: stephanos gr. = wreath, headband.
Holotype: The specimen shown on Plate 9, Fig. 6 and preserved in specimen 775/72.
Paratypes: 779/72, 731/72, 318/72.
Locus typicus: Tönisberg, Lower Rhine.
Stratum typicalum: Middle and Upper Oligocene.
Diagnosis: A species of the genus Hystrichosphaeridium with a small, spherical capsule. This capsule is thin-walled and has a smooth, unfielded surface. It is loosely covered by hollow, short processes, the distal extensions of which may be fused.
Remarks: The processes are 3µm wide at the base and extend up to 10µm at the outermost edges. Distally, the adhesions do not form a shell-like structure, but rather are merely bridge-like connections. A pyloma was not observed. The present specimens show no significant variations in their dimensions.
Dimensions: Capsule length 30μ/32μ, capsule width 26μ/30μ, process length 10μ/12μ (10 measurements). Number of specimens examined: 22.
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Emended description: [Benedek and Sarjeant, 1982, p. 349-350]:
Diagnosis:
Cyst small, spheroidal to broadly ovoidal, skolochorate.
Processes short (roughly one-third to one half of the shortest cyst cross-measurement), tubular and buccinate, the tips flaring widely: they may bear longitudinal fibres or striae, or may lack such features. The length of the processes is relatively constant over the whole cyst. All, or a variable proportion, of the processes are distally united by a perforate membrane, which may appear fibrous and resembles a clinging, damaged spider"s web.
The surface of the phragma may be psilate or may bear a fine ornamentation.
Paratabulation (as determined from the number and position of the processes) probably 4", 0a, 6", 0c, 5-6" ", 0-1p, 1"""" .
Archaeopyle formed by loss of a single precingular paraplate (Type P).
Dimensions:
Holotype: length 36 µm, breadth 30 µm, length of processes c. 8 µm.
Range of dimensions: Length 30-32 µm, breadth 26-30 µm, length of processes 10-12 µm. Material: 16 specimens.
Affinities:
Araneosphaera stephanophora differs from the only other species of this genus, A. araneosa Eaton 1976 from the English Upper Eocene, in its much smaller size and in having processes of more constant length, with a membrane enveloping the whole cyst instead of one confined essentially to the hypotract.
Arenosphaera stephanophora (Benedek, 1972, p.30–31, pl.9, fig.6; text-fig.10) Benedek and Sarjeant, 1981, p.349–350.
Emendation: Benedek and Sarjeant, 1981, p.349–350, as Araneosphaera stephanophora. Holotype: Benedek, 1972,
pl.9, fig.6. Originally Hystrichosphaeridium, subsequently Hystrichosphaeridium?, thirdly (and now)
Araneosphaera. Age: Middle–Late Oligocene.
---------------------------------------------------------------------------------------------------
Original description: [Benedek, 1972, p. 30-31] (translated from German):
Hystrichosphaeridium stephanophorum n. sp.
Derivio nominis: stephanos gr. = wreath, headband.
Holotype: The specimen shown on Plate 9, Fig. 6 and preserved in specimen 775/72.
Paratypes: 779/72, 731/72, 318/72.
Locus typicus: Tönisberg, Lower Rhine.
Stratum typicalum: Middle and Upper Oligocene.
Diagnosis: A species of the genus Hystrichosphaeridium with a small, spherical capsule. This capsule is thin-walled and has a smooth, unfielded surface. It is loosely covered by hollow, short processes, the distal extensions of which may be fused.
Remarks: The processes are 3µm wide at the base and extend up to 10µm at the outermost edges. Distally, the adhesions do not form a shell-like structure, but rather are merely bridge-like connections. A pyloma was not observed. The present specimens show no significant variations in their dimensions.
Dimensions: Capsule length 30μ/32μ, capsule width 26μ/30μ, process length 10μ/12μ (10 measurements). Number of specimens examined: 22.
-----------------------------------------------------------------------------------------------------------------------------------------------------------------
Emended description: [Benedek and Sarjeant, 1982, p. 349-350]:
Diagnosis:
Cyst small, spheroidal to broadly ovoidal, skolochorate.
Processes short (roughly one-third to one half of the shortest cyst cross-measurement), tubular and buccinate, the tips flaring widely: they may bear longitudinal fibres or striae, or may lack such features. The length of the processes is relatively constant over the whole cyst. All, or a variable proportion, of the processes are distally united by a perforate membrane, which may appear fibrous and resembles a clinging, damaged spider"s web.
The surface of the phragma may be psilate or may bear a fine ornamentation.
Paratabulation (as determined from the number and position of the processes) probably 4", 0a, 6", 0c, 5-6" ", 0-1p, 1"""" .
Archaeopyle formed by loss of a single precingular paraplate (Type P).
Dimensions:
Holotype: length 36 µm, breadth 30 µm, length of processes c. 8 µm.
Range of dimensions: Length 30-32 µm, breadth 26-30 µm, length of processes 10-12 µm. Material: 16 specimens.
Affinities:
Araneosphaera stephanophora differs from the only other species of this genus, A. araneosa Eaton 1976 from the English Upper Eocene, in its much smaller size and in having processes of more constant length, with a membrane enveloping the whole cyst instead of one confined essentially to the hypotract.