Ventimolina, Thomsen & Østergaard & Cros, 2015

Thomsen, Helge Abildhauge, Østergaard, Jette Buch & Cros, Lluïsa, 2015, Ventimolina stellata gen. et sp. nov. (Haptophyta, Papposphaeraceae) from Warm Water Regions, Acta Protozoologica 54 (4), pp. 275-281 : 276

Ventimolina gen. nov.

Diagnosis: Small, dimorphic coccosphere. Flagellar pole coccoliths quasicircular and with a calicate central spine that arises from a cruciform central area. The longitudinally flattened calyx comprises four elements one of which is markedly hypertrophied. Body coccoliths oval with a central area cruciform calcification that leads into a short stem that is in turn terminated by a cruciform structure composed of four elements arranged in the shape of a windmill. The rim calcification in both CFC’s and BC’s is limited to a single cycle of directly butting, rod-shaped elements.

Type species: Ventimolina stellata sp. nov. ( Figs 2–6 )

Etymology: from ‘ventus’ (L) meaning wind, ‘mola’ (L) meaning millstone, and ‘ina’ diminutive suffix. The generic name reflects the resemblance between a windmill and the body coccolith calyx.

Ventimolina gen. nov. is morphologically distinct and coccoliths even slightly reminiscent of those described here are not mirrored in any extant or extinct coccolithophore taxa. The new monospecific genus shares features with members of the Papposphaeraceae ( Jordan and Young 1990, Andruleit and Young 2010) in particular species of Pappomonas . An extended discussion of the higher level affinities of Ventimolina gen. nov. is found below.

Figures

Figs 2–6. Ventimolina stellata TEM whole mounts of a single specimen from the Andaman Sea. 2 – whole cell (holotype) with details accounted for in Figs 3–6; 3 – details of circumflagellar coccoliths. The arrow points to a distally slightly convex BC in side view; 4 – detail of body coccolith in lateral view showing clearly the rim and central area calcification and the central superstructure which is slightly convex distally; 5 – body coccoliths showing the single layer rim calcification; 6 – details of the body coccolith calyx (‘windmills’).