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Bryozoa
Escharina woodiana (Busk, 1859)
Nomenclature
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Family: EscharinidaeGenus: Escharina
- holotype: B.M.(N.H.) Palaeont. Dept. D6936
SUMMARY
Colonies are encrusting, multiserial, sheet-like, sometimes irregularly lobate. The ancestrula and early astogeny have not been described. Multiple basal pore chambers are visible ringing the zooids in abraded colonies, about 5 or 6 along each wall directly beneath the areolar pores.
Autozooids are elongated rhomboidal in outline shape, averaging about 0.55 mm long by 0.45 mm wide. The frontal shield is convex, covered by large nodules, and bordered by areolar pores but lacking pseudopores elsewhere on the surface. A raised mucro is present some distance proximally of the orifice, with a smooth area of frontal shield intervening between it and the orifice. The orifice is hemielliptical, wider than long, about 0.10 mm wide in non-ovicellate autozooids but 0.14 mm wide in ovicellate autozooids, with a small, broadly V-shaped sinus in the proximal edge. Oral spines generally number 6 in non-ovicellate autozooids but are lacking in ovicellate autozooids. An uncalcified window is present in the basal walls of the autozooids. The ovicell is globular, with an imperforate surface covered by nodules similar to those of the frontal shield.
Adventitious avicularia are paired either side of the orifice, small in size and represented by oval openings; the pivotal bar appears to be uncalcified.