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Wetzeliella (Wetzeliella) gochtii
Wetzeliella (Wetzeliella) gochtii Costa and Downie, 1976
Holotype: Costa and Downie, 1976, pl. 92, fig.2
Locus typicus: Rupel Clay, Belgium
Stratum typicum: Middle Ologocene
Original diagnosis: Costa and Downie, 1976, p. 609-610
A species of Wetzeliella (Wetzeliella) with usually subpentagonal tests. Endoblast following closely the periblast outline but leaving a narrow and well defined pericoel. All horns reduced to short, blunt projections or absent. The right antapical horn, when present, is markedly shorter than the left antapical horn. Abundant processes, variable in shape, usually rather flexible, open or closed distally.
Dimensions. Holotype: over-all tract length 113 µm, breadth 108 µm; endoblast length 97 µm, breadth 93 µm; apical horn 0 µm; lateral horns 6 µm; antapical horn right 10 µm, left 5 µm; processes length 6-15 µm. Observed range: over-all length 118-107 µm, breadth 111-98 µm; apical horn 13-0 µm; lateral horns 10-4 µm; antapical horn right 12-5 µm, left 5-0 µm; processes length 5-18 µm. Number of specimens measured: 6.
Description. Due to the variable development of the horns, the tracts may be subpentagonal, subrhombic, or subcircular, pentagonal outlines being dominant; in all cases the outline is rounded. The horns, when present, are very short, broad, and blunt. The endophragm lies close to the periphragm but there is always a well defined, although narrow, pericoel, often continuous around the endoblast. The processes vary in shape and characters of the distal endings. Most commonly they are thin-walled, flexible, and frequently with tapering bases. They may be open or closed distally; when open, the distal margin is aculeate or entire, when closed, the distal ending is simple, acuminate, or capitate. In all the specimens observed the opercula are in situ and the archeopyle sutures are frequently difficult to observe.
Remarks. This species resembles W. (W.) symmetrica in the flexible, usually thinwalled processes, but differs from it by having all horns reduced or absent and a more rounded and commonly subpentagonal outline in contrast to the rhombic outlines with four well-developed horns characteristic of W. (W.) symmetrica. Some subcircular individuals of this species resemble W. (A.) homomorpha, from which they are distinguishable by the well-defined pericoel. W. (W.) ovalis also has reduced horns and rounded outlines, but its antapical horns are of about the same length and its processes are shorter, usually thicker-walled, and more rigid than in W. (W.) gochtii.
Holotype: Costa and Downie, 1976, pl. 92, fig.2
Locus typicus: Rupel Clay, Belgium
Stratum typicum: Middle Ologocene
Original diagnosis: Costa and Downie, 1976, p. 609-610
A species of Wetzeliella (Wetzeliella) with usually subpentagonal tests. Endoblast following closely the periblast outline but leaving a narrow and well defined pericoel. All horns reduced to short, blunt projections or absent. The right antapical horn, when present, is markedly shorter than the left antapical horn. Abundant processes, variable in shape, usually rather flexible, open or closed distally.
Dimensions. Holotype: over-all tract length 113 µm, breadth 108 µm; endoblast length 97 µm, breadth 93 µm; apical horn 0 µm; lateral horns 6 µm; antapical horn right 10 µm, left 5 µm; processes length 6-15 µm. Observed range: over-all length 118-107 µm, breadth 111-98 µm; apical horn 13-0 µm; lateral horns 10-4 µm; antapical horn right 12-5 µm, left 5-0 µm; processes length 5-18 µm. Number of specimens measured: 6.
Description. Due to the variable development of the horns, the tracts may be subpentagonal, subrhombic, or subcircular, pentagonal outlines being dominant; in all cases the outline is rounded. The horns, when present, are very short, broad, and blunt. The endophragm lies close to the periphragm but there is always a well defined, although narrow, pericoel, often continuous around the endoblast. The processes vary in shape and characters of the distal endings. Most commonly they are thin-walled, flexible, and frequently with tapering bases. They may be open or closed distally; when open, the distal margin is aculeate or entire, when closed, the distal ending is simple, acuminate, or capitate. In all the specimens observed the opercula are in situ and the archeopyle sutures are frequently difficult to observe.
Remarks. This species resembles W. (W.) symmetrica in the flexible, usually thinwalled processes, but differs from it by having all horns reduced or absent and a more rounded and commonly subpentagonal outline in contrast to the rhombic outlines with four well-developed horns characteristic of W. (W.) symmetrica. Some subcircular individuals of this species resemble W. (A.) homomorpha, from which they are distinguishable by the well-defined pericoel. W. (W.) ovalis also has reduced horns and rounded outlines, but its antapical horns are of about the same length and its processes are shorter, usually thicker-walled, and more rigid than in W. (W.) gochtii.