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Hystrichosphaera ramosa
Hystrichosphaera ramosa (Ehrenberg, 1837b, pl.1, fig.15) Deflandre 1937b, p.64.
NOW Spiniferites. Originally Xanthidium ramosum (acritarch), subsequently (and now) Spiniferites ramosus, thirdly Hystrichosphaera ramosa, fourthly Ovum hispidum subsp. ramosum (combination not validly published, acritarch), fifthly Bion ramosum (acritarch).
Taxonomic junior synonyms: Xanthidium (as Hystrichosphaera) furcatum, according to Davey and Williams (1966a, p.29–33); Galea korykos and Hystrichosphaeridium echinoides, both according to Sarjeant (1983, p.91–92); Areoligera birama, according to Morgenroth (1968, p.550); Geodia? tripunctata, by implication in Sarjeant (1964b, p.175), who considered Geodia? tripunctata to be a taxonomic junior synonym of Hystrichosphaera furcata; Hystrichosphaera (now Spiniferites) bulloidea, according to Harland (1977b, p.101–102) — however, Lentin and Williams (1981, p.259) retained Hystrichosphaera (as and now Spiniferites) bulloideus; Homotryblium distinctum, according to Jain and Garg (1982, p.69), who considered Homotryblium distinctum to be a taxonomic junior synonym of Spiniferites ramosus subsp. ramosus.
Motile equivalent: Gonyaulax spinifera (Claparède and Lachmann, 1859) Diesing, 1866, according to Dodge (1989, p.289).
The nomenclatural type of the genus Hystrichosphaera remains the holotype of Hystrichosphaera furcata.
This combination was not validly published in Wetzel (1933b, p.35) since the generic name was not validly published until 1937. The validity/authorship of this name may need to be reconsidered as it appears that Ehrenberg (1837b) did not provide a description.
Holotype: not designated
Lectotype: Ehrenberg, 1838, pl.1, fig.5 (designated by Davey and Williams, 1966)
Stratum typicum: Feuerstein von Delitzsch, no. XXV, Germany
Locus typicus: Late Cretaceous
Translation Gocht, 1969: Geological Suvey of Canada
Emended diagnosis: Davey and Williams, 1966, p. 32
A species of Hystrichosphaera possessing a thin walled central body, smooth, reticulate or granular. Gonal +/- sutural processes always extending beyond confines of sutural crests, solid or hollow, the latter closed distally, Typical gonal processes trifurcate, sutural processes bifurcate, both commonly terminating distally in a small bifurcation.
Gocht, 1969, p.31:
The exceptionally variable group comprising Davey and Williams" "furcata- ramosa complex" was combined by those authors into the species ramosa.
In the Tertiary of Meckelfeld, mainly the early "furcata" type was found, with not very long, furcate processes which also have spines at the end. Sometimes the processes also resemble those of H. pseudofurcata (Klumpp), but in that case they are usually differentiated by the fact that a narrow strengthening ridge extends from base to apex. Apical plate 1" (on the ventral side) is divided, sometimes by a sagittal line and sometimes by a ridge, into two fields, so that there are four apical fields instead of three. The triangular plate 6"" in the precingular series is usually separated from the longitudinal furrow not by a list, but only by a line.
The inner body is smooth or granulate. On some specimens the process bases are
connected by hems. At the antapex, there may be a sail-like extension. Certain forms with long processes approximate the early "ramosa" type. It is often difficult or impossible to assign individual specimens to a particular variety.
A well preserved specimen of "Hystrichosphaera cornuta" Gerlach with a long apical process was found in three samples. According to Morgenroth, 1966, who investigated the range of variation of H. furcata, also this form falls within the range of this group.
Occurrence: Paleocene- Middle Oligocene.
Hystrichosphaera cf. ramosa (Ehrenberg)
The inner membrane of this interesting form is of medium thickness and shows a distinct, labyrinthine surface sculpture. The outer membrane is relatively fragile. The processes show one or more furcations. This form, which perhaps still falls within the range of variation of the ramosa group, is represented only by a few specimens. There are also a few more individuals with less distinct, finer sculpture.
Measurements: maximal diameter 102-127 µm. Main body 57-68 µm.
Occurrence: Early Eocene- ?Late Eocene.
NOW Spiniferites. Originally Xanthidium ramosum (acritarch), subsequently (and now) Spiniferites ramosus, thirdly Hystrichosphaera ramosa, fourthly Ovum hispidum subsp. ramosum (combination not validly published, acritarch), fifthly Bion ramosum (acritarch).
Taxonomic junior synonyms: Xanthidium (as Hystrichosphaera) furcatum, according to Davey and Williams (1966a, p.29–33); Galea korykos and Hystrichosphaeridium echinoides, both according to Sarjeant (1983, p.91–92); Areoligera birama, according to Morgenroth (1968, p.550); Geodia? tripunctata, by implication in Sarjeant (1964b, p.175), who considered Geodia? tripunctata to be a taxonomic junior synonym of Hystrichosphaera furcata; Hystrichosphaera (now Spiniferites) bulloidea, according to Harland (1977b, p.101–102) — however, Lentin and Williams (1981, p.259) retained Hystrichosphaera (as and now Spiniferites) bulloideus; Homotryblium distinctum, according to Jain and Garg (1982, p.69), who considered Homotryblium distinctum to be a taxonomic junior synonym of Spiniferites ramosus subsp. ramosus.
Motile equivalent: Gonyaulax spinifera (Claparède and Lachmann, 1859) Diesing, 1866, according to Dodge (1989, p.289).
The nomenclatural type of the genus Hystrichosphaera remains the holotype of Hystrichosphaera furcata.
This combination was not validly published in Wetzel (1933b, p.35) since the generic name was not validly published until 1937. The validity/authorship of this name may need to be reconsidered as it appears that Ehrenberg (1837b) did not provide a description.
Holotype: not designated
Lectotype: Ehrenberg, 1838, pl.1, fig.5 (designated by Davey and Williams, 1966)
Stratum typicum: Feuerstein von Delitzsch, no. XXV, Germany
Locus typicus: Late Cretaceous
Translation Gocht, 1969: Geological Suvey of Canada
Emended diagnosis: Davey and Williams, 1966, p. 32
A species of Hystrichosphaera possessing a thin walled central body, smooth, reticulate or granular. Gonal +/- sutural processes always extending beyond confines of sutural crests, solid or hollow, the latter closed distally, Typical gonal processes trifurcate, sutural processes bifurcate, both commonly terminating distally in a small bifurcation.
Gocht, 1969, p.31:
The exceptionally variable group comprising Davey and Williams" "furcata- ramosa complex" was combined by those authors into the species ramosa.
In the Tertiary of Meckelfeld, mainly the early "furcata" type was found, with not very long, furcate processes which also have spines at the end. Sometimes the processes also resemble those of H. pseudofurcata (Klumpp), but in that case they are usually differentiated by the fact that a narrow strengthening ridge extends from base to apex. Apical plate 1" (on the ventral side) is divided, sometimes by a sagittal line and sometimes by a ridge, into two fields, so that there are four apical fields instead of three. The triangular plate 6"" in the precingular series is usually separated from the longitudinal furrow not by a list, but only by a line.
The inner body is smooth or granulate. On some specimens the process bases are
connected by hems. At the antapex, there may be a sail-like extension. Certain forms with long processes approximate the early "ramosa" type. It is often difficult or impossible to assign individual specimens to a particular variety.
A well preserved specimen of "Hystrichosphaera cornuta" Gerlach with a long apical process was found in three samples. According to Morgenroth, 1966, who investigated the range of variation of H. furcata, also this form falls within the range of this group.
Occurrence: Paleocene- Middle Oligocene.
Hystrichosphaera cf. ramosa (Ehrenberg)
The inner membrane of this interesting form is of medium thickness and shows a distinct, labyrinthine surface sculpture. The outer membrane is relatively fragile. The processes show one or more furcations. This form, which perhaps still falls within the range of variation of the ramosa group, is represented only by a few specimens. There are also a few more individuals with less distinct, finer sculpture.
Measurements: maximal diameter 102-127 µm. Main body 57-68 µm.
Occurrence: Early Eocene- ?Late Eocene.