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Xenascus ceratioides
Xenascus ceratioides (Deflandre, 1937) Lentin and Williams, 1973
Originally Hystrichosphaera, subsequently Pseudoceratium, thirdly Spiniferites, fourthly Phoberocysta, fifthly (and now) Xenascus.
Taxonomic junior synonym: Endoceratium (now Xenascus) perforatum, according to Davey and Verdier (1971, p.27) — however, Yun Hyesu (1981, p.62) retained Endoceratium (as Xenascus) perforatum;
Taxonomic junior synonym: Xenascus australensis, according to Davey and Verdier (1971, p.26) — however, Lentin and Williams (1985, p.374) retained Xenascus australensis;
Taxonomic junior synonym: Odontochitina blastema, according to Davey and Verdier (1971, p.27) — however, Stover and Helby (1987a, p.128) retained Odontochitina (as Xenascus) blastema..
Holotype: Deflandre, 1937, pl.12 [al. pl.9], figs.7-8; Fensome et al., 1991, fig.1-p.601; fig.1 p.605
Paratype: Deflandre, 1937
Locus typicus: Paris, France
Stratum typicum: Senonian
Translation Deflandre, 1937: LPP
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999
Xenascus ceratioides (Deflandre, 1937b) Lentin and Williams, 1973. Deflandre (1937b, p.66-67) noted that one pole bears a single strong, elongate horn, which seems to be readily detachable since it is missing on the second specimen, the paratype. There is a subcylindrical, forked horn, on the other half. There are several spines and horns around the equator and at various locations on the test. Size: length 172 µm, width 40 µm.
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Deflandre 1937, p. 66-67: Hystrichosphaera ceratioides
Diagnosis (annotated): this species shows the general characteristic of an equatorial system of elongate plates. There are also a number of furcate appendices, unfortunately partially broken in the best specimen presented here. Since the poles of the organism cannot be distinguished, it has been oriented arbitrarily. The upper part bears a blunt cone as well as several other protruberances, whereas the oppsite pole bears a single, heavy and elongate horn, which seems easily detachable, because it is missing in the second specimen, the paratype. A subcylindrical furcate horn, situated on the anterior part, is present on both specimens (holotype and paratype). Several spines and horns are arranged around the equator and on various locations on the body. As is shown in the illustration, the posterior part shows sutures which confine a system of plates.
Dimensions: total length about 172 µm, breadth about 40 µm.
Originally Hystrichosphaera, subsequently Pseudoceratium, thirdly Spiniferites, fourthly Phoberocysta, fifthly (and now) Xenascus.
Taxonomic junior synonym: Endoceratium (now Xenascus) perforatum, according to Davey and Verdier (1971, p.27) — however, Yun Hyesu (1981, p.62) retained Endoceratium (as Xenascus) perforatum;
Taxonomic junior synonym: Xenascus australensis, according to Davey and Verdier (1971, p.26) — however, Lentin and Williams (1985, p.374) retained Xenascus australensis;
Taxonomic junior synonym: Odontochitina blastema, according to Davey and Verdier (1971, p.27) — however, Stover and Helby (1987a, p.128) retained Odontochitina (as Xenascus) blastema..
Holotype: Deflandre, 1937, pl.12 [al. pl.9], figs.7-8; Fensome et al., 1991, fig.1-p.601; fig.1 p.605
Paratype: Deflandre, 1937
Locus typicus: Paris, France
Stratum typicum: Senonian
Translation Deflandre, 1937: LPP
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999
Xenascus ceratioides (Deflandre, 1937b) Lentin and Williams, 1973. Deflandre (1937b, p.66-67) noted that one pole bears a single strong, elongate horn, which seems to be readily detachable since it is missing on the second specimen, the paratype. There is a subcylindrical, forked horn, on the other half. There are several spines and horns around the equator and at various locations on the test. Size: length 172 µm, width 40 µm.
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Deflandre 1937, p. 66-67: Hystrichosphaera ceratioides
Diagnosis (annotated): this species shows the general characteristic of an equatorial system of elongate plates. There are also a number of furcate appendices, unfortunately partially broken in the best specimen presented here. Since the poles of the organism cannot be distinguished, it has been oriented arbitrarily. The upper part bears a blunt cone as well as several other protruberances, whereas the oppsite pole bears a single, heavy and elongate horn, which seems easily detachable, because it is missing in the second specimen, the paratype. A subcylindrical furcate horn, situated on the anterior part, is present on both specimens (holotype and paratype). Several spines and horns are arranged around the equator and on various locations on the body. As is shown in the illustration, the posterior part shows sutures which confine a system of plates.
Dimensions: total length about 172 µm, breadth about 40 µm.