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Hystrichosphaeridium majus
Hystrichosphaeridium majus Lejeune-Carpentier, 1940; Emendation: Lejeune-Carpentier and Sarjeant, 1981, p.12, as Amphorosphaeridium majus.
NOW Exochosphaeridium. Originally Hystrichosphaeridium, subsequently Polysphaeridium?, thirdly Cordosphaeridium, fourthly Dapsilidinium? (combination not validly published), fifthly Amphorosphaeridium, sixthly (and now) Exochosphaeridium.
Taxonomic junior synonyms: Baltisphaeridium (as Exochosphaeridium) bifidum and Exochosphaeridium bifidum var. involutum (as Exochosphaeridium bifidum subsp. involutum), both according to Peyrot (2011, p.284).
Holotype: Lejeune-Carpentier, 1940, text-fig.13; Streel et al., 1977, pl.1, fig.7; Lejeune-Carpentier and Sarjeant, 1981, pl.2, figs.6–7; text-fig.7.
Age: Late Cretaceous.
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Original description (Lejeune-Carpentier, 1940):
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Emendation (Lejeune-Carpentier and Sarjeant, 1981):
Emended diagnosis : Cyst spheroidal to ovoidal, skolochorate. Processes tubular, often fibrous. They appear to be essentially intratabular inn position and number around 60, being less than one-half the cyst diameter in length. The processes are typically broad-based by vary greatly in thickness and in style of distal termination, the latter including bifurcate, trifurcate, foliate, digitate and aculeate forms. Archeopyle single-plate precingular, type P.
Holotype: Specimens XIX-133: Lodged in the collection of the Laboratoire de Paléontologie, Université de Liège, Belgium: figures by Lejeune-Carpentier, 1940, fig. 13, and herein, Pl.2: 6-7 and Text-fig. 7.
Type horizon and Locality: Flint filling of echinoid, Craie de Spiennes (=Formatie van Gulpen of Felder, 1975), upper Cretaceous (Senonian), Hallembaye, Limbourg Basin, Belgium.
Dimensions: Holotype (in polar view) – diameter of cyst 64.5 µm, length of processes around 21.6 µm.
Range of dimensions: maximum cross-measurement of cyst 55-57 µm.
Emended description: The holotype is seen in antapical view: the antapical process is surrounded by a groove of polygonal outline, simulating the shape of a single antapical paraplate. Many of the other, larger processes are considered to be likewise intratabular in position, though in many instances there are clearly several processes per paraplate. The thinner processes appear to correspond to cingular and sulcul paraplates; However it is possible that some may be sutural in situation. In view of the position of the holotype in the enclosing flint, the apical surface is hard to see and our reconstruction of it must certainly be inaccurate in detail. However, the size, shape and position of the archeopyle make it clear that this was formed by loss of a single precingular paraplate (probably 3’’). The surface of the phragma shows a dense ornamentation of granules and/or punctae. The processes, formed from periphragm only, have this ornament to a reduced degree by are commonly fibrous.
NOW Exochosphaeridium. Originally Hystrichosphaeridium, subsequently Polysphaeridium?, thirdly Cordosphaeridium, fourthly Dapsilidinium? (combination not validly published), fifthly Amphorosphaeridium, sixthly (and now) Exochosphaeridium.
Taxonomic junior synonyms: Baltisphaeridium (as Exochosphaeridium) bifidum and Exochosphaeridium bifidum var. involutum (as Exochosphaeridium bifidum subsp. involutum), both according to Peyrot (2011, p.284).
Holotype: Lejeune-Carpentier, 1940, text-fig.13; Streel et al., 1977, pl.1, fig.7; Lejeune-Carpentier and Sarjeant, 1981, pl.2, figs.6–7; text-fig.7.
Age: Late Cretaceous.
------------------------------------------
Original description (Lejeune-Carpentier, 1940):
------------------------------------------
Emendation (Lejeune-Carpentier and Sarjeant, 1981):
Emended diagnosis : Cyst spheroidal to ovoidal, skolochorate. Processes tubular, often fibrous. They appear to be essentially intratabular inn position and number around 60, being less than one-half the cyst diameter in length. The processes are typically broad-based by vary greatly in thickness and in style of distal termination, the latter including bifurcate, trifurcate, foliate, digitate and aculeate forms. Archeopyle single-plate precingular, type P.
Holotype: Specimens XIX-133: Lodged in the collection of the Laboratoire de Paléontologie, Université de Liège, Belgium: figures by Lejeune-Carpentier, 1940, fig. 13, and herein, Pl.2: 6-7 and Text-fig. 7.
Type horizon and Locality: Flint filling of echinoid, Craie de Spiennes (=Formatie van Gulpen of Felder, 1975), upper Cretaceous (Senonian), Hallembaye, Limbourg Basin, Belgium.
Dimensions: Holotype (in polar view) – diameter of cyst 64.5 µm, length of processes around 21.6 µm.
Range of dimensions: maximum cross-measurement of cyst 55-57 µm.
Emended description: The holotype is seen in antapical view: the antapical process is surrounded by a groove of polygonal outline, simulating the shape of a single antapical paraplate. Many of the other, larger processes are considered to be likewise intratabular in position, though in many instances there are clearly several processes per paraplate. The thinner processes appear to correspond to cingular and sulcul paraplates; However it is possible that some may be sutural in situation. In view of the position of the holotype in the enclosing flint, the apical surface is hard to see and our reconstruction of it must certainly be inaccurate in detail. However, the size, shape and position of the archeopyle make it clear that this was formed by loss of a single precingular paraplate (probably 3’’). The surface of the phragma shows a dense ornamentation of granules and/or punctae. The processes, formed from periphragm only, have this ornament to a reduced degree by are commonly fibrous.