Karsella daviesi ( Hofker, 1966 ) SCHLAGINTWEIT, 2021

SCHLAGINTWEIT, FELIX, 2021, Orbitolina Daviesi Hofker, 1966: A Forgotten Orbitolinidae From The Thanetian Of Pakistan And Its Taxonomic Status, Acta Palaeontologica Romaniae 17 (1), pp. 41-48 : 46

Karsella daviesi ( Hofker, 1966) comb. nov.

1941 Orbitolina sp. – Davies, p. 317 (fide Hofker, 1966). 1966 Orbitolina daviesi n. sp. – Hofker, p. 12, pl. 2, figs. 10-14, pl. 3.

1997 Karsella hottingeri n. gen., n. sp. – Sirel, p. 210, pl. 1, figs. 1-10, pl. 2, figs. 1-4.

Non 2005 Karsella sp. – Tentor and Venturini, fig. 8, 9?, 10-12 [ Schroedericonus turriculus (Hottinger & Drobne) ].

2006 Karsella hottingeri Sirel – Hottinger, fig. 41K-L.

2010 Karsella hottingeri Sirel – Afzal, p. 115, pl. 14, figs. 5-10,?11-13?, 14.

2014 “ Orbitolina ” daviesi J. Hofker jun. – Hottinger, p. 51, pl. 4.9, fig. 2.

2018 Karsella hottingeri Sirel – Cruz-Abad, p. 84, fig. 78A-E (reproduction of Sirel, 1997).

2018 “ Orbitolina ” daviesi Hofker – Cruz-Abad, fig. 78F-H.

2020 Karsella hottingeri Sirel – Schlagintweit, figs. 1, 2A-B (reproductions of Sirel, 1997, Hottinger, 2006, and Afzal, 2010).

Description: Test large, high-conical to slightly cylindroconical with moderately convex base. The megalospheric embryo is situated in a central position at the rounded apex and presents a diameter of up to 0.5 mm. It consists of an irregular ellpisoidal proloculus, a large deuteroconch with partitions (supraembryonic zone) and a few broad peri-embryonic chambers (“subembryonic zone”) that are sporadically subdivided. The neanic stage consists of up to 27 uniserial chambers subdivided into marginal, broad radial, and reduced central zones. There are 5-7 chambers per the last millimeter of the axial cone length. The marginal zone is complex, displaying several orders of beams and rafters. The main partitions (septula), are triangular in axial section, increase in thickeness towards the cone centre and alternate in position between subsequent chambers. In transverse sections, the septula display a zig-zag pattern with associated radially arranged foramina piercing the septa obliquely. The septula form an irregular network displaying oblique stolon axes in the reduced central zone. Wall agglutinated.

Occurrences: Karsella daviesi (Hofker) comb. nov. is known from the Thanetian of Turkey (Sirel, 1997), and Pakistan ( Hofker, 1966; Hottinger, 2006; Afzal, 2010).