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Exochosphaeridium bifidum ssp. involutum
Exochosphaeridium bifidum ssp. involutum (Davey, 1969) Lentin and Williams, 1973; emend. Marheinecke, 1992
Originally Exochosphaeridium bifidum var. involutum, subsequently Exochosphaeridium bifidum subsp. involutum.
Taxonomic senior synonym: Hystrichosphaeridium (now Exochosphaeridium) majus according to Peyrot (2011, p.284). The possibility of this synonymy was earlier postulated by Marheinecke (1992, p.51).
Holotype: Davey, 1969, pl.2, fig.3
Locus typicus: South Africa
Stratum typicum: Campanian-Maastrichtian
Translation Marheinecke, 1992: LPP
Original diagnosis: Davey, 1969, p.29
A variety of E. bifidum (Clarke and Verdier) possessing a small number of (less than 50 %) of hollow processes.
Emended description: Marheinecke, 1992, p.52
Cyst sphaeroidal to subsphaeroidal. Wall thick, composed of pedium and spongious luxuria, developing a net-like tegillum. Luxuria forms c. 50-50 thin processes, most of which are thin and solid. Some peocesses are slightly broadened, hollow, tubiforme as in Amphorosphaeridium. Base of processes broadened and striate, distal ends usually bifurcate or multifurcate, sometimes recurvate. Processes intraareate, three to four processes per area. Cingulum marked by a row of processes, seldom connected by a weak ridge. Sulcal processes in generall thinner, but not always distinguishable. Apical process larger and branched. Antapical process consists of two fused processes. Archeopyle precingular 3"", operculum secate.
Originally Exochosphaeridium bifidum var. involutum, subsequently Exochosphaeridium bifidum subsp. involutum.
Taxonomic senior synonym: Hystrichosphaeridium (now Exochosphaeridium) majus according to Peyrot (2011, p.284). The possibility of this synonymy was earlier postulated by Marheinecke (1992, p.51).
Holotype: Davey, 1969, pl.2, fig.3
Locus typicus: South Africa
Stratum typicum: Campanian-Maastrichtian
Translation Marheinecke, 1992: LPP
Original diagnosis: Davey, 1969, p.29
A variety of E. bifidum (Clarke and Verdier) possessing a small number of (less than 50 %) of hollow processes.
Emended description: Marheinecke, 1992, p.52
Cyst sphaeroidal to subsphaeroidal. Wall thick, composed of pedium and spongious luxuria, developing a net-like tegillum. Luxuria forms c. 50-50 thin processes, most of which are thin and solid. Some peocesses are slightly broadened, hollow, tubiforme as in Amphorosphaeridium. Base of processes broadened and striate, distal ends usually bifurcate or multifurcate, sometimes recurvate. Processes intraareate, three to four processes per area. Cingulum marked by a row of processes, seldom connected by a weak ridge. Sulcal processes in generall thinner, but not always distinguishable. Apical process larger and branched. Antapical process consists of two fused processes. Archeopyle precingular 3"", operculum secate.