Squinabollum Dumitrică, 1970

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 : 134

Genus Squinabollum Dumitrică, 1970

Type species: Clistophaena fossilis Squinabol, 1903 = Squinabollum fossile (Squinabol)

Remarks. The species from the upper Valanginian of Sardinia here referred to Squinabollum is the oldest known member of this genus. According to O’Dogherty ( 1994), Squinabollum has its origin in Hiscocapsa asseni (Tan, 1927) , a four-chambered species originated in early Barremian or Hauterivian and disappeared in the Turonian. However, its occurrence in the upper Valanginian of Sardinia proves that the origin of this genus is older, and that H. asseni cannot be its probable forerunner, although the two species seem to be closely related: both have a two-segmented cephalis and the morphology of the abdomen of H. asseni resembles somehow the morphology of what is here considered as the thoracic collar in S. elegans n. sp. (see below). What differentiates the two species and genera is that S. elegans has a short apical horn present always in the species of the genus Squinabolum , and absent in H. asseni , but present in the type-species of Hiscocapsa O’Dogherty, 1994 . Later, Odogherty et al. (2017) included Squinabolum in the family Arcanicapsidae Takemura, 1986 As concerns the stratigraphic range of the genus Squinabolum new data from the radiolarian fauna of the Coniacian sample DV54 from the Deva Beds, Romania (see Dumitrică & Carter, 1999; Dumitrică, 2004 for the locality of this sample), prove that it is still present and rather common at this level where it is represented by a species with the last globose segment characterized by having an additional cortical layer around its distal half.

Range. Valanginian to Coniacian.