Svinitzium irregulare Dumitrică, 2022

Dumitrica, Paulian, Dieni, Iginio & Massari, Francesco, 2022, Valanginian Radiolarians Of Ne Sardinia (Italy) In The Frame Of The Weissert Event, Acta Palaeontologica Romaniae 18 (2), pp. 97-159 : 145

publication ID

https://doi.org/ 10.35463/j.apr.2022.02.06

persistent identifier

https://treatment.plazi.org/id/EE35878D-0E47-AA1F-54AF-F8DDFC6DFB4A

treatment provided by

Felipe

scientific name

Svinitzium irregulare Dumitrică
status

sp. nov.

Svinitzium irregulare Dumitrică n. sp.

Figs. 14r, t View Fig

Description. Shell multicyrtid conico-cylindrical consisting of 6-8 or probably more segments. First four segments increase in diameter as added forming a conical body without apical horn. Cephalis and thorax smooth-surfaced, and collar boundary marked by a circumferential row of small circular pores. Following two segments, representing abdomen and first postabdominal segment,

are well inflated, costate and separated by a deep postlumbar constriction. The abdomen has a circumferential row of small circular pores, and the first postabdominal segment two parallel circumferential row of pores on the inflate portion. The following two to four segments, depending on the length of shell, have concave outline with a poreless circumferential band in the deep portion separated on both sides by high and slightly nodular circumferential crests and by a row of pores. Inner intersegmental platforms marked outside by the high circumferential and slightly nodular crest. Nodes may be separated by small shallow depressions. On the distal segments ( Fig. 14t View Fig ) the row of relict pores characteristic of the genus is not visible.

Studied material. Two specimens.

Holotype. Figure 14t View Fig , col. MGP-PD, stub PD120 -OZ834- R10-10 .

Paratype. Figure 14r View Fig , coll. MGP-PD, stub PD120 - OZ836- R08-05 .

Dimensions. Length of shell with 6 segments 171 μm, with 8 segments 212 μm, maximum diameter 103-108 μm.

Remarks. The two illustrated specimens, although different in length of test and number of segments, have similar proximal and distal parts. In the holotype, there is a transitional segment between these well distinct portions. The external strictures of the species do not correspond to the internal planiform partitions between segments but to their middle part, these partitions corresponding to the expanded parts of the segments like in the Parvicingulidae .

Etymology. From the Latin irregularis, -e = irregular.

Range and occurrence. Known only in the S’Ozzastru section.

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