Xitus, Pessagno, 1977
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publication ID |
https://doi.org/ 10.35463/j.apr.2022.02.06 |
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persistent identifier |
https://treatment.plazi.org/id/EE35878D-0E4F-AA17-54AF-FF30FD1BF7E4 |
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treatment provided by |
Felipe |
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scientific name |
Xitus |
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Xitus vermiculatus (Renz, 1974)
Fig. 16e View Fig
1974 Eucyrtidium vermiculatum Renz , p. 792, pl. 8, figs. 17-19; pl. 11, fig. 22.
?1977b Xitus spineus Pessagno, p. 56, pl. 10, figs. 3, 12, 16, 20.
1977b Xitus plenus Pessagno, p. 55, pl. 12, fig. 15.
1981 Xitus vermiculatus (Renz) – Schaaf, p. 441, pl. 19, figs. 6a, 6b.
1981 Xitus sp. – Schaaf, p. 441, pl. 4, fig. 12.
1981 Xitus sp. indet. – Schaaf, pl. 21, figs. 10a, b.
1982 Novixitus tuberculatus Wu & Li , p. 69, pl. 2, fig. 6.
1988 Parvicingula ? sp. – Thurow, p. 403, pl. 6, fig. 10.
1993 Xitus vermiculatus (Renz) – Ellis, p. 978, pl. 4, figs. 12, 13.
1994 Novixitus (?) tuberculatus (Wu) – Jud, p. 86, pl. 13, figs. 7-9.
1994 Xitus elegans (Squinabol) – O’Dogherty, p. 126, pl. 11, figs. 9-14.
?1994 Novixitus (?) daneliani Jud , p. 85, pl. 13, fig. 6.
?1995 Novixitus tuberculatus Wu & Li – Baumgartner et al., p. 338, pl. 5693, figs. 1-5.
?1995 Novixitus (?) daneliani Jud – Baumgartner et al., p. 336, pl. 5524, fig.2.
1995 Xitus plenus Pessagno – Takahashi & Ishii, pl. 3, fig. 12.
1997 Xitus vermiculatus (Renz) – Dumitrică et al., p. 57, pl. 12, figs. 5, 10.
1998 Xitus asymbatos (Foreman) – Vishnevskaya & De Wever, p. 257, pl. 1, figs. 11, 12.
2003 Xitus elegans (Squinabol) – Zyabrev et al., fig. 3.55. 2009 Novixitus (?) tuberculatus Wu – Ishii et al., p. 347, pl. 19, fig. 2.
Studied material. The illustrated specimen from sample OZ838 (coll. MGP, stub PD120-OZ838-R05-07) and another specimen from sample OZ833.
Dimensions. Length of shell 220 µm, maximum diameter 124 µm.
Remarks. The species is rather long-ranged in the lower Cretaceous (see below) and very characteristic by its conical shell and by having two circumferential rows of tubercles: a bigger one in the middle of segments and a smaller one along the segment partition.
Novixitus (?) daneliani Jud seems to be synonymous of Xitus vermiculatus with an additional distal segment provided with three spines. The whole test, except this last segment, is perfectly similar to Renz’s species. In this situation one could consider that X. vermiculatus is an incompletely developed specimen of N. daneliani , or a N. daneliani specimen that during the fossilisation or laboratory treatments lost the lasts segments. This possibility is suggested by the specimen illustrated in Baumgarten et al. (1995) from the lower Hauterivian of the Murguceva section, Svinița ( Romania), in which one can see that the connection of the last segment bearing the three spines with the main part of test is weak.
Range and occurrence. The species seems to be cosmopolitan in the Lower Cretaceous of Tethys from Valanginian to late Aptian according to O’Dogherty (1994).
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