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Hystrichosphaera furcata
Hystrichosphaera furcata (Ehrenberg, 1837b, pl.1, figs.12,14) Deflandre, 1937b, p.61.
Originally Xanthidium furcatum (acritarch), subsequently Hystrichosphaera furcata, thirdly Ovum hispidum subsp. furcatum (acritarch), fourthly Spiniferites furcatus (combination not validly published).
Taxonomic senior synonym: Xanthidium (as Hystrichosphaera, now Spiniferites) ramosum, according to Davey and Williams (1966a, p.29–33).
Taxonomic junior synonym: Geodia? tripunctata (acritarch), according to Sarjeant (1964b, p.175).
The nomenclatural type of the genus Hystrichosphaera remains Hystrichosphaera furcata (although no holotype has been designated).
This combination was not validly published in Wetzel (1933b, p.34) since the generic name Hystrichosphaera 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
Age: Late Cretaceous
Reference: Wall, 1967, pl.14, fig.1-2
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Rossignol 1964, p. 85-86, pl. 1, fig.11, pl. 3, fig.9
Hystrichosphaera furcata (Ehr.) O.Wetz. emend. Ross.
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Supplemental description: Wall, 1967, p. 99
The test is ovoid with broadly rounded apices; circular in polar view. The girdle is narrow, descending and displaced by slightly more than its width ventrally; the longitudinal furrow is weakly inclined, narrow anteriorly, only extending on to the epitheca for a short distance but broadening posteriorly. The tabulation (3-4", 0a, 6"", 6g, 5-6""", 1p, 1"""") reflected primarily by very low sutural septa which are no more than traces between spine bases. In the apical series there are two pentagonal dorsal plate-areas and two smaller, linear ventral areas; the septum separating the latter is small and variously developed. The precingular areas are subrectangular except for plate-area 6"" which is triangular, The archeopyle is developed from plate-area 3"", The postcingular plates are also subrectangular apart from the first which, when visible, lies to the left of the furrow and is a weak linear structure comparable with that found in extant Gonyaulax. The posterior intercalary area is small, anterior to the large, subrectangular antapical area. Spines are the dominant ornamentation and are situated at the corners of plates in most instances but can occur in between along the sutures. Septa are not usually well developed. The most complex spines, which are initially trifurcate and secondarily bifurcate, are found along the girdle, at the head of the furrow, around the posterior intercalary plate and at the dorsal antapical points. In these positions, two parallel branchlets of a spine may be directed along the course of a suture-trace. Intratabular areas are more or less smooth.
Originally Xanthidium furcatum (acritarch), subsequently Hystrichosphaera furcata, thirdly Ovum hispidum subsp. furcatum (acritarch), fourthly Spiniferites furcatus (combination not validly published).
Taxonomic senior synonym: Xanthidium (as Hystrichosphaera, now Spiniferites) ramosum, according to Davey and Williams (1966a, p.29–33).
Taxonomic junior synonym: Geodia? tripunctata (acritarch), according to Sarjeant (1964b, p.175).
The nomenclatural type of the genus Hystrichosphaera remains Hystrichosphaera furcata (although no holotype has been designated).
This combination was not validly published in Wetzel (1933b, p.34) since the generic name Hystrichosphaera 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
Age: Late Cretaceous
Reference: Wall, 1967, pl.14, fig.1-2
---------------------------------
Rossignol 1964, p. 85-86, pl. 1, fig.11, pl. 3, fig.9
Hystrichosphaera furcata (Ehr.) O.Wetz. emend. Ross.
---------------------------------
Supplemental description: Wall, 1967, p. 99
The test is ovoid with broadly rounded apices; circular in polar view. The girdle is narrow, descending and displaced by slightly more than its width ventrally; the longitudinal furrow is weakly inclined, narrow anteriorly, only extending on to the epitheca for a short distance but broadening posteriorly. The tabulation (3-4", 0a, 6"", 6g, 5-6""", 1p, 1"""") reflected primarily by very low sutural septa which are no more than traces between spine bases. In the apical series there are two pentagonal dorsal plate-areas and two smaller, linear ventral areas; the septum separating the latter is small and variously developed. The precingular areas are subrectangular except for plate-area 6"" which is triangular, The archeopyle is developed from plate-area 3"", The postcingular plates are also subrectangular apart from the first which, when visible, lies to the left of the furrow and is a weak linear structure comparable with that found in extant Gonyaulax. The posterior intercalary area is small, anterior to the large, subrectangular antapical area. Spines are the dominant ornamentation and are situated at the corners of plates in most instances but can occur in between along the sutures. Septa are not usually well developed. The most complex spines, which are initially trifurcate and secondarily bifurcate, are found along the girdle, at the head of the furrow, around the posterior intercalary plate and at the dorsal antapical points. In these positions, two parallel branchlets of a spine may be directed along the course of a suture-trace. Intratabular areas are more or less smooth.