Back
Vozzhennikovia villosa

Vozzhennikovia villosa (Eisenack and Cookson, 1960) Stover and Evitt, 1978; Emendation: Morgan, 1977, p.134,136, as Dioxya villosa.

Now Dioxya. Originally (and now) Dioxya, subsequently Vozzhennikovia.
Lentin and Williams, 1981, retained this species in Dioxya Cookson and Eisenack, 1958.

Holotype: Eisenack and Cookson, 1960, pl.2, fig.15; Morgan, 1977, pl.2, fig.6
Locus typicus: Moora Bore, Perth Basin, Australia
Stratum typicum: Albian

Original description: Eisenack and Cookson, 1960, p. 10: Dioxya villosa
Shell broadly fusiform to almost sphaerical, with a truncate apical process surmounded by two short bristles; antapical process inconspicuous, pointed, situated in the mid-line or somewhat laterally. Shell-membrane thin, completely invested with minute spinules.

Emended description: Morgan, 1977, p. 134: Dioxya villosa
Pericyst ambitus ovoidal, apex drawn into a broad, truncate apical horn, antapex drawn into two, short, symmetrically located antapical horns which are unequal in length. Epipericyst slightly larger than hypopericyst. Ambital outline widest in pericingular region. Endocyst ovoidal, with two unequal antapical horns, closely appressed against pericyst except in the vicinity of the apical horn, where a small pericoel is developed. Periphragm bears dense, nontabular, 2-3 µm, sharp spines, aligned only in two rows delineating the pericingulum. Perisulcus not discernible. Endophragm psilate. Archeopyle standard hexa la, periphragm and endophragm closely appressed in archeopyle region.
Dimensions: 52-60 µm long and 32-43 µm broad.
Comments: An intercalary archeopyle is visibly open only along the right side of the operculum on the holotype (Pl. 2, fig. 6) but is fully developed on other specimens.

Affinities:
Morgan, 1977, p. 134: Dioxya villosa
Ovoidal to subpentagonal ambitus, dense, 2-3 µm, sharp, nontabular spines and normal hexa Ia archaeopyle are characteristic for D. villosa. For detailed comparison see treatment of D. armata.
Feedback/Report bug