Syracosphaera periperforata ( Kleijne 1991 ) var. periperforata Archontikis, Young, Cros

Archontikis, Odysseas A., Young, Jeremy R. & Cros, Lluïsa, 2020, Taxonomic Revision and Classification of Extant Holococcolithophores Previously Placed in the Genus Anthosphaera Kamptner emend. Kleijne 1991, Acta Protozoologica 59 (3 - 4), pp. 121-139 : 132-134

Syracosphaera periperforata ( Kleijne 1991) var. periperforata Archontikis, Young, Cros HOL

Synonymy: Anthosphaera periperforata Kleijne (1991) , p. 41, Plate IX, Figs. 3–4 ; Winter and Siess- er (1994), p. 149, Fig. 166; Aubry (1999), p. 248, Fig. 6 (upper panel).

Anthosphaera periperforata type 2 Cros (2001), p. 81, Pl. 56, Figs. 3–4 ; Cros and Fortuño (2002), p. 59, Fig. 87C; Young et al. (2003), p. 90, Pl. 42, Figs. 3 , 6.

Anthosphaera sp. Dimiza (2006), p. 83, Pl. XXVI, Fig. 6.

Description: Coccosphere, spherical in shape, com- posed of c. 40–80 BCs and c. 5–8 CFCs. BCs ellipti- cal rim one crystallite wide, perforate cycle with c. 16 radial struts that show anticlockwise obliquity in distal view; central structure cone-shaped. A short central apical boss always occurs at the top of the protrusion. CFCs elliptical with well-formed arch, supported by ro- bust columns of crystallites, ending distally in a central spine. Additional buttress-like struts of crystallites may also be present within the arch ( Plate 4 , Fig. 2 ).

Remarks: BCs’ central structure is of conical shape and consistently presents an apical boss on top of its distal cover. The width of the rim is of one crystallite and is connected to the central structure by struts of three to five microcrystals.

Dimensions: Coccosphere diameter c. 5.5 μm. BCs c. 1.0 μm long x c. 0.8 μm wide. CFCs c. 1.0 μm long and wide; distal process c. 1.3 μm high.

Figures

Plate 3. Scale bars = 1μm 1–2. Syracosphaera lafourcadii (Lecal) Archontikis, Young, Cros comb. nov. HOL Complete coccospheres composed of CFCs that bear low distal processes (see arrows) and BCs with distal covers made of irregularly ar- ranged crystallites. 3–4. Syracosphaera origami (Cros and McGrane) Archontikis, Young, Cros comb. nov. HOL Coccospheres with highly ornamented CFCs showing triangle-shaped distal processes (fig. 3, arrow) and BCs with an organic base-plate in proximal view (fig. 4, arrow a) and a rim that supports delicate struts of crystallites holding the origami-like paper boat distal covers (fig. 4, arrow b) in distal view.

Plate 4. Syracosphaera periperforata (Kleijne) Archontikis, Young, Cros comb. nov. HOL Scale bars = 1μm

Fig. 2. Schematic representation and terminology of Anthosphaera coccosphere and holococcolith types.