Praeconosphaera Yang, 1993

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 : 106

Genus Praeconosphaera Yang, 1993

Type species: Conosphaera sphaeroconus Rüst, 1898 .

Praeconosphaera sphaeroconus (Rüst, 1898)

Fig. 7a

1898 Conosphaera sphaeroconus Rüst , p. 13-14, pl. 4, fig. 8.

1973 Actinomids, gen. and sp. indet. – Foreman, p. 272, pl. 1, figs. 4, 6.

1986 Praeconocaryomma globosa Wu , p. 357, pl. 1, figs. 15, 19.

1993 Praeconosphaera sphaeroconus (Rüst) – Yang, p. 105, pl. 17, figs. 2, 6, 12, 16, 23.

1997 Praeconosphaera sphaeroconus (Rüst) – Dumitrică et al., p. 21, pl. 3, fig. 3.

Remarks. The species is well recognizable by its bigger size and cupola-shaped or hemispherical tubercles, each tubercle rounded and with one or two pores on the top, and also with thicker intervening bars as compared with the intervening bars in the intertuberculate areas. Although no microsphere was remarked until present in this species, it should have existed because other members of the family Acaeniotylidae have it.

Range and occurrence: Lower Tithonian to Hauterivian, cosmopolitan.

Figures

Fig. 7 a - Praeconosphaera sphaeroconus (Rüst OZ826. b-d - Praeconosphaera antiqua (Parona): b - OZ834, c - OZ838, d - OZ825. e - Tritrabs ewingi (Pessagno), arm in lateral view, OZ836. f-h - Emiluvia chica Foreman, OZ836; f - face view, g - lateral view from a spine, h - lateral view of a broken specimen showing the medullary test. i - Pantanellium sp. 1, OZ825. j, l-n1 - Pantanellium squinabolli (Tan): j - OZ834; l, m - OZ834, n - OZ836; m1, n1, details of inner wall of pores. k - Pantanellium sp. 2, OZ834. o – Pantanellium cf. squinaboli (Tan), OZ836; p - Praeconocaryomma copiosa Wu, OZ836. r - Praeconocaryomma thurowi Dumitrică n. sp., OZ836. s, t - Triactoma tithonianum Rüst, side views; s - OZ834, broken off specimen showing medullary shell; t - OZ825, equatorial view, t1 – face view; s1, t2 - detail of the base of spines of figs. s and t, respectively, x800. Figs. a-h, l-n x200; i-k, o-r x300; s, t x400, m1, n1 x500.