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Hystrichosphaeridium tubiferum ssp. brevispinum
From Fensome et al., 2019:
Hystrichsphaeridium tubiferum ssp. brevispinum (Davey and Williams, 1966b, p.58, pl.10, fig.10) Lentin and Williams, 1973, p.80. Emendation: Marheinecke, 1992, p.61, as Hystrichosphaeridium proprium subsp. brevispinum. Holotype:
Davey and Williams, 1966b, pl.10, fig.10; Bujak et al., 1980, pl.8, figs.10–12; Fauconnier and Masure, 2004, pl.47, figs.1–4. Originally Hystrichosphaeridium tubiferum var. brevispinum, subsequently (and now) Hystrichosphaeridium tubiferum subsp. brevispinum, thirdly Hystrichosphaeridium proprium subsp. brevispinum. Lentin and Williams (1993, p.336) retained this taxon as a subspecies of Hystrichosphaeridium tubiferum. Taxonomic senior synonym: Micrhystridium (as Dapsilidinium?, now Litosphaeridium) fucosum, according to Below (1982c, p.29) — however, Lentin and Williams (1985, p.190) retained Hystrichosphaeridium tubiferum subsp. brevispinum. Age: Early Eocene.
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Original dignosis: Davey and Williams, 1966, p. 58
A variety of Hystrichsphaeridium tubiferum with processes rarely exceeding one-third of the diameter of the central body.
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Emended description Marheinecke, 1992, p. 61 (translated from German):
Description: Cyst chorate, sphaeroidal to subsphaeroidal. Wall composed of pedium and luxuria. The luxuria forms hollow, broadly tubiform intraareate processes, distally open with a weakly aculeate, rounded margin. Accedation formula: 1?pr, 4', 6", 6c, 5-6"", 1p, 1"", 3-5s.
Archeopyle: apical, ?pr+1'+2'+3'+4', operculum secat, foederat (?pr+1'+2'+3'+4'). The luxuria is usually alveolate and forms a foveolate tegillum between the processes. Forms with a compactly fused pedium/luxuria form a smooth surface. The apical, precingular, postcingular, and antapic processes form subangular to almost square attachment scars. The cingular processes form oval scars and an oval cross-section, the sulcal processes a round cross-section, round scars, and are overall slimmer.
The length of the processes reaches, at most, one-third of the central capsule diameter.
Additional note: The change was made due to the much greater morphological similarity to the species Hystrichosphaeridium proprium established here than to Hystrichosphaeridium tubiferum. This emendation replaces the very brief description in DAVEY & WILLIAMS 1966b.
Comparison: To Hystrichosphaeridium proprium proprium the greatly reduced length of the processes. This feature is constant, as DAVEY & WILLIAMS 1966b also pointed out in their original diagnosis.
Specimens: 27.
Statistics: Length central capsule: 37(39)41, width central capsule: 32(34)37, length of processes: 5-11, archaeopyle diameter: 22(23)25.
Measured specimens: 8.
Known range: Maastrichtian - Eocene.
Hystrichsphaeridium tubiferum ssp. brevispinum (Davey and Williams, 1966b, p.58, pl.10, fig.10) Lentin and Williams, 1973, p.80. Emendation: Marheinecke, 1992, p.61, as Hystrichosphaeridium proprium subsp. brevispinum. Holotype:
Davey and Williams, 1966b, pl.10, fig.10; Bujak et al., 1980, pl.8, figs.10–12; Fauconnier and Masure, 2004, pl.47, figs.1–4. Originally Hystrichosphaeridium tubiferum var. brevispinum, subsequently (and now) Hystrichosphaeridium tubiferum subsp. brevispinum, thirdly Hystrichosphaeridium proprium subsp. brevispinum. Lentin and Williams (1993, p.336) retained this taxon as a subspecies of Hystrichosphaeridium tubiferum. Taxonomic senior synonym: Micrhystridium (as Dapsilidinium?, now Litosphaeridium) fucosum, according to Below (1982c, p.29) — however, Lentin and Williams (1985, p.190) retained Hystrichosphaeridium tubiferum subsp. brevispinum. Age: Early Eocene.
---------------------------------------------------------------------------------------------------
Original dignosis: Davey and Williams, 1966, p. 58
A variety of Hystrichsphaeridium tubiferum with processes rarely exceeding one-third of the diameter of the central body.
---------------------------------------------------------------------------------------------------
Emended description Marheinecke, 1992, p. 61 (translated from German):
Description: Cyst chorate, sphaeroidal to subsphaeroidal. Wall composed of pedium and luxuria. The luxuria forms hollow, broadly tubiform intraareate processes, distally open with a weakly aculeate, rounded margin. Accedation formula: 1?pr, 4', 6", 6c, 5-6"", 1p, 1"", 3-5s.
Archeopyle: apical, ?pr+1'+2'+3'+4', operculum secat, foederat (?pr+1'+2'+3'+4'). The luxuria is usually alveolate and forms a foveolate tegillum between the processes. Forms with a compactly fused pedium/luxuria form a smooth surface. The apical, precingular, postcingular, and antapic processes form subangular to almost square attachment scars. The cingular processes form oval scars and an oval cross-section, the sulcal processes a round cross-section, round scars, and are overall slimmer.
The length of the processes reaches, at most, one-third of the central capsule diameter.
Additional note: The change was made due to the much greater morphological similarity to the species Hystrichosphaeridium proprium established here than to Hystrichosphaeridium tubiferum. This emendation replaces the very brief description in DAVEY & WILLIAMS 1966b.
Comparison: To Hystrichosphaeridium proprium proprium the greatly reduced length of the processes. This feature is constant, as DAVEY & WILLIAMS 1966b also pointed out in their original diagnosis.
Specimens: 27.
Statistics: Length central capsule: 37(39)41, width central capsule: 32(34)37, length of processes: 5-11, archaeopyle diameter: 22(23)25.
Measured specimens: 8.
Known range: Maastrichtian - Eocene.