Crococapsa zweilii (Jud, 1994)

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 : 133

Crococapsa zweilii (Jud, 1994)

Figs. 6h ; 12a, c, d

?1982 Sethocapsa lagenaria Wu & Li , p. 70. pl. 2, fig. 9.

1991 radiolari – Dieni & Massari, fig. 23h.

1994 Sethocapsa (?) zweilii Jud , p. 106, pl. 20, figs. 12- 14.

2017 Hiscocapsa zweilii (Jud) – Xu & Luo, fig. 5J.

Description. The last (postabdominal) segment is much larger than the cephalo-abdominal body, resulting in a sphero-conical shell with relatively well marked intersegmental constrictions. Cephalis conical, imperforate with rounded apex separated from thorax by a circle of very small pores. Thorax trapezoidal in lateral view with very small circular pores. Abdomen trapezoidal too, with pores larger than those of the thorax and polygonally framed. Postabdominal segment very large, globular with 5-6 large, laterally opened ocelli on half a perimeter. It has small circular pores on the inner side of wall separat- ed by large polygonal, commonly hexagonal, frames on the surface. Size of frames becomes smaller distally.

Studied material. Three specimens in OZ825, OZ826 and OZ836, coll. MGP-PD, stub PD120 - OZ825- R12-03 and 33, PD120 - OZ826- R12-03 , and PD120 - OZ836- R07-15 .

Dimensions. Total length 188-208 µm, diameter of postabdomen 128-148 µm

Remarks. This species is very close to C. horokanaiensis (Kawabata, 1988) and probably Crococapsa accincta (Steiger, 1992) . However, the latter species has practically no intersegmental constrictions; its last segment has a smaller diameter by comparison with the other species and, above all, its apical end is rather acute and very small that does not suggest a two-chambered cephalis. C. horokanaiensis differs from C. zweilii by being much longer, by having well marked intersegmental constrictions and circular pores with polygonal frames. All these three species have laterally opened ocelli. Another species similar to C. zweilii , and probably its senior synonym, is Sethocapsa (?) lagenaria Wu & Li, 1982 . Unfortunately, its figured position is oblique, and the ocelli are difficult to see; they seem to be apically oblique instead of laterally directed.

Range. Berriasian to lower Hauterivian, UAZ 6-26 of Jud ( 1994).

Figures

Fig. 6 Radiolarians illustrated by Dieni & Massari, 1991 in their Fig. 23c-i which correspond to the letters from that article: c - Favosyringium affine (Rüst), d - Pseudoxitus seriola - Dumitrică, e - Williriedellum peterschmittae Schaaf, f - Cryptamphorella Dumitricăi Schaaf, g – Ristola nakatonbetsensis Tumanda, h - Crococapsa zweili (Jud), i - Cryptamphorella circumthoracica Dumitrică n. sp., Fig. c x200, figs. d-i x250.

Fig. 12 b - Crococapsa cf. horokanaiensis (Kawabata), OZ834. a, c, d - Crococapsa zweilii (Jud): a, OZ826; c, OZ836; d, OZ825. e-h - Crococapsa uterculus (Parona): e, f, h - OZ834, g - OZ825. i-o - Ocellicapsa ruthae Dumitrică n. sp.: i - OZ837, j - OZ837, k - OZ836, i - OZ834, m - OZ824, n - OZ838, n1 - detail of cephalothoracic body, arrow shows the place of very small pores at the boundary between the two parts of cephalic cavity, o - OZ825. p, r, t, v - Squinabolum elegans Dumitrică n. sp.: p - OZ824, r - OZ826, t - OZ836, s - Amphipyndax zyabrevi Dumitrică n. sp. - OZ825. u - Campanomitra pulchella (Rüst), OZ836. v - OZ834. w, x - Archaeodictyomitra inflata Dumitrică n. sp.: w - OZ839, x - OZ834. Figs. a, c-h, u x250, all the others x300.