Thanarla cf. pulchra (Squinabol, 1903)

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 : 143-144

Thanarla cf. pulchra (Squinabol, 1903)

Figs. 13o , 14g

?1988 Thanarla sp. A – Thurow, p. 406, pl. 7, fig 12.

Studied material. Two specimens in samples OZ825 and OZ834.

Dimensions. Length of shell without distal projections 180 µm, diameter 120-125 µm.

Remarks. This species is close in size and morphology to T. pulchra , from which it differs by having more or less marked constrictions on the inflate distal part of shell and a similarly deeper constriction between the proximal conical part and the distal inflated part. It is possible that this morphology evolved in time to originate the Albian Thanarla sp. A of Thurow where the undulations become much more marked.

Occurrence. Two specimens in the upper Valanginian of Sardinia .

Figures

Fig. 13 a, b - Apiaromitra apiarium (Rüst): a - OZ836, b - OZ839, a1 - detail of ornamentation of last segment, b1 - detail of ornamentation of penultimate segment. c - Archaeodictyomitra robustovum Dumitrică n. sp., OZ837. d - Archaeodictyomitra sp., OZ839. e, f - Archaeodictyomitra mitra Dumitrică: e - OZ838, f - OZ824. g-k - Archaeodictyomitra massarii Dumitrică n. sp.: g - OZ834, g1 - detail of surface x1000. h - OZ834, i - OZ839, j - OZ834, k - OZ839; k1 - detail of wall showing the cavernous structure, k2 - detail of surface. l, p - Archaeodictyomitra longipora Dumitrică n. sp., OZ836; l - portion of surface of p much magnified showing the elevated intercostal area. m - Apiaromitra tyaughtonensis (Cordey), OZ837. n, t - Archaeodictyomitra dienii Dumitrică n. sp.: n - OZ836, t - OZ837. o - Thanarla cf. pulchra (Squinabol), OZ824. r - Archaeodictyomitra judae Dumitrica n. sp., OZ839. s - Archaeodictyomitra humerosa Dumitrică n. sp., OZ839. Figs. a, b x250, k1 and k2 x450, all the others x300.

Fig. 14 a - Archaeodictyomitra conicoscalaris Dumitrică n. sp., OZ839. b, f - Archaeodictyomitra humerosa Dumitrică n. sp.: b - OZ834, f - OZ824. c - Archaeodictyomitra pumila Dumitrică n. sp., OZ834. d, e - Archaeodictyomitra conica (Aliev), OZ824. g - Thanarla cf. pulchra (Squinabol), OZ825. h - Thanarla pulchra (Squinabol), OZ839. i, j – Mictyoditra thiensis (Tan), OZ836. k - Archaeodictyomitra excellens (Tan), OZ839. l - Archaeodictyomitra sp., OZ836. m, n - Loopus nudus (Schaaf): m - OZ838, n - OZ834. o - Loopus cf. primitivus (Matsuoka & Yao), OZ834. p, p1, p2 - Svinitzium depressum (Baumgartner), p1, p2 - details of penultimate segmental band showing relic pores of parvicingulid type or other types, OZ824. Figs. r, t - Svinitzium (?) irregulare Dumitrică n. sp.: r - OZ 836, t - OZ834. s, u - Pseudodictyomitra cf. carpatica (Lozynyak): s - OZ834, u - OZ 824. Figs. b, n x250, the others x300.