Williriedellum gilkeyi Dumitrică, 1972

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 : 121

Williriedellum gilkeyi Dumitrică, 1972

Figs. 10i, i 1

1972 Williriedellum (?) gilkeyi Dumitrică , p. 841, pl. 3, figs. 4, 6; pl. 4, figs. 1, 2.

1981 Williriedellum gilkeyi Dumitrică – Schaaf, p. 440, pl, 2, figs. 6a-c.

1988 Wiliriedellum gilkeyi Dumitrică (pars) – Thurow, p. 408, pl. 8, figs. 10, 13, non fig. 14.

1991 Wiliriedellum gilkeyi Dumitrică – Aguado et al., text-fig. 7.17.

1993 Wiliriedellum gilkeyi Dumitrică – Aguado et al., pl. 3, fig. 5.

1994 Cryptamphorella gilkeyi (Dumitrică 1972) – O’Dogherty, p. 210, pl. 34, figs. 9-14.

Studied material. A single specimen in sample OZ838, coll. MGP-PD, stub PD120-OZ838-R05-04 and 04a.

Dimensions. Length of shell 140 µm, of abdomen 103 µm, diameter of abdomen 123 µm.

Remarks. As remarked in the original description (Dumitrică, 1972), this species was questionably assigned to the genus Williriedellum due to the lack of a distal view in order to see whether the holotype has or not an aperture. O’Dogherty ( 1994) mentioned that the abdomen has no aperture and, consequently, assigned the taxon to the genus Cryptamphorella Dumitrică, 1970 . Moreover, this author initially established the age of the species as Albi- an on the basis of foraminifera, but later he ascertained the range as Barremian-lower Aptian. The specimen illustrated in the present paper ( Fig. 10i 1 ) proves that the aperture exists, and that the species belongs to the genus Williriedellum . Its aperture is a distal circular opening with a short protruding rim.

Range and occurrence. Upper Valanginian to lower Apti- an, Tethys.

Figures

Fig. 10 a-c1 - Hemicryptocapsa (?) bellireticulum (Wu & Li): a - OZ825, b - OZ836. c - OZ838, c1 - OZ824. d-f, j-j2 - Williriedellum labeosum Dumitrică n. sp.: d, e, j-j2, OZ837, f - OZ834. g, g1 - Cryptamphorella circumthoracica Dumitrică n. sp., OZ838; g1 - view of apical part. h, k-o – Cryptamphorella dumitricai Schaaf: h - detail of sutural pore, k - OZ825, l - OZ 824, m - OZ838, n-o, OZ839. i, i1- Williriedellum gilkei Dumitrică, OZ838. p - Zhamoidellum ovum Dumitrică, OZ839. r - Williriedellum cordiforme Dumitrică n. sp., OZ837. s, s1 - Williriedellum occultithorax Dumitrică n. sp. in lateral and obliquely apical views, OZ826. t-t2 – Cryptamphorella crassilabrosa Dumitrică n. sp., OZ837: t, t1 - holotype in two positions, t2 – sutural pore much magnified showing inside the wall of the hidden thorax. Figs. a-f, i, h, k-o, r x250; g, gi, h, t, t1 x300.

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).