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Gochtodinium simplex
Gochtodinium simplex (Bujak, 1979, p.312-313, pl.2, fig.10; pl.3, figs.1-12; text-figs.4B,8F) Lentin and Vozzhennikova, 1989, p.228.
Holotype: Bujak, 1979, pl.3, figs.7-12; Bujak et al., 1980, pl.15, fig.5; Fensome et al., 1995, figs.1-5 - p.1793.
Originally Gochtodinium, subsequently (and now) Wetzeliella.
Age: Mid Eocene (see Aubry, 1986).
Original Diagnosis: Bujak 1979, p. 312-313: Gochtodinium simplex
Pericyst ambitus rhomboidal. Apical and left antapical horns rounded to conical; right antapical horn strongly reduced or absent; pericingular horns tapering, rectangular or flared. Pericyst breadth equal to or greater than length (text-fig. 5) . Endocyst ambitus rounded rhomboidal. Periphragm laevigate to chagrinate with hollow, distally closed processes. Processes simple or branched into 2 or occasionally 3 branches, equal or unequal. distally bulbous or of constant width and with evexate terminations. Process terminations never aculeate. Process distribution random or occasionally suggesting simulate arrangement. Processes may be longer and more densely arranged on the horns and pericingulum. Pericingulum defined by alignment of isolated or proximally united processes. Endophragm with strong granulation apically, antapically and laterally, and weaker granulation on the remaining ambital periphery and paracingulum. Paratabulation lacking or weakly suggested by rare, simulate process arrangement. When evident. paratabulation is peridinioid with the fourth precingular paraplate 4" broader than the second intercalary 2a. Archeopyle quadra intercalary, soleiform. resulting from the displacement of paraplate 2a, trapezoidal with side Q3 longer than side Q1. Perioperculum and endoperculum adjacent and remaining attached to the cyst along side Q1.
Dimensions. Pericyst length 95-125 µ, breadth 105- 140µ. Endocyst length 75-95µ, breadth 75-100µ. Mximum process length on a specimen 7-12 µ. (n = 15, see text-fig. 5) .
Remarks: Bujak 1979, p. 312-313
G. simplex is characterized by its shape. soleiform archeopyle and spinate ornament. It is distin-guished from Gochtodinium spinula, n. sp.. by having longer processes. It differs from species of Wetzeliella in never having aculeate processes and in the mode of opercular attachment. Wetzeliella gochtii (Costa and Downie) Lentin and Williams, described from the Middle Oligocene of southern England, sometimes possesses a few processes with evexate endings, but mostly has open aculeate and closed capitate processes. It also differs in lacking well-developed pericingular horns. Costa and Downie (1976, p. 595) noted the earliest occurrence in the Barton Beds of ""an unpublished species which is apparently related, if not synonymous, to W. (W.) symmetrica. " The unpublished species, now formally described herein as G. simplex, has a pericyst shape similar to that of W. symmetrica, but the latter species differs in having aculeate processes (Weiler, 1956, pl. 2, figs. 1-3, text-figs. 2-5).
Distribution: Upper Eocene, southern England (this paper). Upper Eocene, Lower and Middle Oligocene, offshore southeastern Canada (Williams and Bujak, 1977b).
Holotype: Bujak, 1979, pl.3, figs.7-12; Bujak et al., 1980, pl.15, fig.5; Fensome et al., 1995, figs.1-5 - p.1793.
Originally Gochtodinium, subsequently (and now) Wetzeliella.
Age: Mid Eocene (see Aubry, 1986).
Original Diagnosis: Bujak 1979, p. 312-313: Gochtodinium simplex
Pericyst ambitus rhomboidal. Apical and left antapical horns rounded to conical; right antapical horn strongly reduced or absent; pericingular horns tapering, rectangular or flared. Pericyst breadth equal to or greater than length (text-fig. 5) . Endocyst ambitus rounded rhomboidal. Periphragm laevigate to chagrinate with hollow, distally closed processes. Processes simple or branched into 2 or occasionally 3 branches, equal or unequal. distally bulbous or of constant width and with evexate terminations. Process terminations never aculeate. Process distribution random or occasionally suggesting simulate arrangement. Processes may be longer and more densely arranged on the horns and pericingulum. Pericingulum defined by alignment of isolated or proximally united processes. Endophragm with strong granulation apically, antapically and laterally, and weaker granulation on the remaining ambital periphery and paracingulum. Paratabulation lacking or weakly suggested by rare, simulate process arrangement. When evident. paratabulation is peridinioid with the fourth precingular paraplate 4" broader than the second intercalary 2a. Archeopyle quadra intercalary, soleiform. resulting from the displacement of paraplate 2a, trapezoidal with side Q3 longer than side Q1. Perioperculum and endoperculum adjacent and remaining attached to the cyst along side Q1.
Dimensions. Pericyst length 95-125 µ, breadth 105- 140µ. Endocyst length 75-95µ, breadth 75-100µ. Mximum process length on a specimen 7-12 µ. (n = 15, see text-fig. 5) .
Remarks: Bujak 1979, p. 312-313
G. simplex is characterized by its shape. soleiform archeopyle and spinate ornament. It is distin-guished from Gochtodinium spinula, n. sp.. by having longer processes. It differs from species of Wetzeliella in never having aculeate processes and in the mode of opercular attachment. Wetzeliella gochtii (Costa and Downie) Lentin and Williams, described from the Middle Oligocene of southern England, sometimes possesses a few processes with evexate endings, but mostly has open aculeate and closed capitate processes. It also differs in lacking well-developed pericingular horns. Costa and Downie (1976, p. 595) noted the earliest occurrence in the Barton Beds of ""an unpublished species which is apparently related, if not synonymous, to W. (W.) symmetrica. " The unpublished species, now formally described herein as G. simplex, has a pericyst shape similar to that of W. symmetrica, but the latter species differs in having aculeate processes (Weiler, 1956, pl. 2, figs. 1-3, text-figs. 2-5).
Distribution: Upper Eocene, southern England (this paper). Upper Eocene, Lower and Middle Oligocene, offshore southeastern Canada (Williams and Bujak, 1977b).