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Rhombodinium ornatum
Rhombodinium? ornatum (Wilson, 1967) Stover and Evitt, 1978
Now Wilsonidium. Originally Wetzeliella, subsequently (and now) Wilsonidium, thirdly Rhombodinium?. Stover and Evitt, 1978 considered this to be a "provisionally accepted species" of Rhombodinium. Lentin and Williams, 1981 retained this species in Wilsonidium Lentin and Williams, 1976.
Holotype: Wilson, 1967, fig.33
Locus typicus: Waipawa, Hawkes Bay, New Zealand
Stratum typicum: Early Eocene
Original description: Wilson, 1967, p.481, 492: Wetzeliella (Wetzeliella) ornata
Periphragm pentagonal, angular, with five well developed horns although left antapical horn substantially shorter than right. Ornament very distinctive, comprises short, rectangular pillars (1=1-3 µm) arranged in rows and usually capped by a fairly stout membranous fiber. The small rectangular perforations (I up to 3 µm) so formed are especially apparent along the periphragm margin. Archeopyle large, trapezium-shaped. Capsule large, circular. Tabulation not clear although process rows appear to correspond to sutures. Transverse girdle always present.
Dimensions: Holotype: l = 156 µm, h = 151 µm, capsule 99 µm X 102 µm, apical horn 30 µm, Ieft antapical horn 14 µm, right antapical horn 25 µm, side horns 25 µm. Another specimen (SM 123): l124 µm, b=135 µm, capsule 74 µm X 88 µm, ap. h. 25 µm, l. ant. h. 8 µm, r. ant. h. 22 µm, lat. h. 22 µm.
Affinities:
Wilson, 1967, p.492: Wetzeliella (Wetzeliella) ornata
This species is of the same general type as Wetzeliella (W.) clathrata Eis., W. (W.) coelothrypa Williams and Downie, and W. (W.) edwardsii Wilson since the processes are linked distally. It is readily distinguished by the very short length of the processes and the small rectangular nature of the perforations so formed.
Now Wilsonidium. Originally Wetzeliella, subsequently (and now) Wilsonidium, thirdly Rhombodinium?. Stover and Evitt, 1978 considered this to be a "provisionally accepted species" of Rhombodinium. Lentin and Williams, 1981 retained this species in Wilsonidium Lentin and Williams, 1976.
Holotype: Wilson, 1967, fig.33
Locus typicus: Waipawa, Hawkes Bay, New Zealand
Stratum typicum: Early Eocene
Original description: Wilson, 1967, p.481, 492: Wetzeliella (Wetzeliella) ornata
Periphragm pentagonal, angular, with five well developed horns although left antapical horn substantially shorter than right. Ornament very distinctive, comprises short, rectangular pillars (1=1-3 µm) arranged in rows and usually capped by a fairly stout membranous fiber. The small rectangular perforations (I up to 3 µm) so formed are especially apparent along the periphragm margin. Archeopyle large, trapezium-shaped. Capsule large, circular. Tabulation not clear although process rows appear to correspond to sutures. Transverse girdle always present.
Dimensions: Holotype: l = 156 µm, h = 151 µm, capsule 99 µm X 102 µm, apical horn 30 µm, Ieft antapical horn 14 µm, right antapical horn 25 µm, side horns 25 µm. Another specimen (SM 123): l124 µm, b=135 µm, capsule 74 µm X 88 µm, ap. h. 25 µm, l. ant. h. 8 µm, r. ant. h. 22 µm, lat. h. 22 µm.
Affinities:
Wilson, 1967, p.492: Wetzeliella (Wetzeliella) ornata
This species is of the same general type as Wetzeliella (W.) clathrata Eis., W. (W.) coelothrypa Williams and Downie, and W. (W.) edwardsii Wilson since the processes are linked distally. It is readily distinguished by the very short length of the processes and the small rectangular nature of the perforations so formed.