Doliocapsa O’Dogherty, Goričan & Gawlick, 2017

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 : 128

Genus Doliocapsa O’Dogherty, Goričan & Gawlick, 2017

Type species. Stichomitra (?) stecki O’Dogherty, Goričan & Dumitrică, 2006.

Remarks. According to the original diagnosis, we include in this genus species with small, hornless, simple and usually poreless spherical cephalis, and conical shell consisting usually of four or maximum five segments, the last one larger than the others and with a large terminal aperture. Aperture is either funnel-shaped (11k1) or has a protruding circular rim separated from the shell of the distal segment by a circular depression ( Fig. 11m 1 ). This type resembles the segmental partitions of many multicyrtid nassellarians (see, for example, Pessagno 1977b, pl. 7, figs. 19, 21, 26), suggesting that the distal segment should have had a small, or a very thin-walled terminal inverted conical or cap-shaped fifth segment usually dissolved after the death of the organism, or some distal projections.

The species included in this genus can be assembled into 2 groups:

a) one group is similar to the type species and consists of conical species with chambers increasing regularly in diameter as added and with a large distal aperture. This group can include: Stichomitra (?) stecki O’Dogherty, Goričan & Dumitrică, 2006, Doliocapsa erbae Dumitrică n. sp., D. favopora Dumitrică n. sp. and D. mediterranea Dumitrică n. sp.

b) the second group includes species with the last segment much greater and the distal aperture simple, without a protruding rim surrounded by a circular depression. It would comprise the following species: Doliocapsa aitai Dumitrică n. sp. D., lagunculoides Dumitrică n. sp., D. tuberculata Dumitrică n. sp., D. weisserti Dumitrică n. sp. and D. utoi Dumitrică n. sp.

Figures

Fig. 11 a-b1 - Hiscocapsa grutterinki (Tan): a, OZ834, b, OZ839. c, c1, d, g - Hiscocapsa (?) ventriosa Dumitrică n. sp.: b, OZ839, c, OZ836, c1, aperture, g - complete specimen, V40, Svinița, Romania. e - Doliocapsa utoi Dumitrică n. sp., OZ824. f, f1, h, h1 - Hiscocapsa rugosacutis Dumitrică n. sp., OZ826. i-i1 - Hiscocapsa aitai Dumitrică n. sp., OZ824. p, s -Hiscocapsa lagunculoides Dumitrică n. sp., OZ834, OZ838; p1, s1- distal apertures of both specimens. j - Squinabollum cf. elegans Dumitrică n. sp., OZ826. k, k1 - Doliocapsa weisserti Dumitrică n. sp., OZ834. l - Hiscocapsa tuberculata Dumitrică n. sp., OZ826. m, m1, n - Doliocapsa erbae Dumitrică n. sp., OZ834. o – Doliocapsa favopora Dumitrică n. sp., OZ834. r - Doliocapsa mediterranea Dumitrică n. sp., OZ834. Figs. a-d, j x250; figs. c1, e, e1, f, f1, g, h, i, i1, k, k1, l, p, r x300, m-o, p1 x400.

Fig. 1 Geologic map of the Siniscola area, NE Sardinia (from Dieni & Massari, 1971, updated in 1986). Legend: a - Recent and present alluvial deposits (Holocene). b - Scree deposits (Würm-Holocene). c - Detrital cones mostly composed of gelifraction limestone clasts (“éboulis ordonnés”) (Würm-Holocene). d - Uncemented alluvial cones mostly consisting of limestone clasts (Würm-Holocene). e - Terraced alluvial deposits composed of clasts of basement rocks (Riss?). f - Tightly cemented and dismembered alluvial cones mostly made up of gelifraction limestone clasts (Riss?). g - Cuccuru ’e Flores Conglomerate: polymict, chaotic and thick-bedded breccia and stratified sandstone (middle Eocene). h - Siniscola Marl: grey and grey-yellow marl and, in the upper part, alternating marl/marly limestone with ammonites and very abundant radiolarians and sponge spicules (late Valanginian). i - Schiriddè Limestone: light-brown cherty limestone and limestone with marly interbeds, containing ammonites, radiolarians, sponge spicules and calpionellids (early Valanginian). j - Monte Bardia Limestone: thick-bedded to massive white limestone in places bioconstructed, with corals, nerineids, etc. (early Tithonian - late Berriasian). k - S’Adde Limestone: light-brown to grey fine-grained, well-bedded limestone, condensed with hardgrounds near the base, cherty in the upper part, with ammonites and belemnites in the uppermost part (latest Bathonian - earliest Tithonian). l - Dorgali Formation: well bedded quartz-arenitic and locally ooidal brown dolostone (middle-late Bathonian). m - Crystalline basement (phyllite, micaschist, paragneiss, quartzite, etc.) (Palaeozoic). n - Fault. o - Attitude of beds and schistosity planes. p - Limits of slumped masses of Jurassic formations (Quaternary). q - Concave-upward slip surfaces delimiting rotational slumps (Quaternary). r - Edge of fluvial terrace. s - Quarry. A-A’ Trace of the geological section of Fig. 2. (extracted from Bottini et al., 2018).