Back
Dolichodinium uncinatum
Dolichodinium uncinatum (Michoux, 1988, p.36,38, pl.7, figs.1–6; pl.8, figs.1–7: text-fig.12) Williams et al. 2015, p.303.
Originally Wetzeliella, subsequently (and now) Dolichodinium.
Holotype: Michoux, 1988, pl.7, figs.1–5; text-fig.12.
Locus typicus: "Marnes a discocyclines" Louer section, France
Age: early Eocene.
Original diagnosis: Michoux, 1988, p. 36
Circumcavate to cornucavate peridinioid cyst, rhomboidal in outline, strongly compressed dorso-ventrally. Periphragm bears short, hook-like, possibly sutural processes. Archeopyle intercalary (I/2a). Perioperculum elongated, narrowing and adnate anteriorly; endoperculum free.
Original description: Michoux, 1988, p. 36
The cyst is rhomboidal in outline, with four well developed horns: one apical, two lateral and one (left) antapical; the right antapical horn is strongly reduced. The apical and antapical horns taper distally, while the lateral horns are rounded to square-ended, and of variable length. Their distal ends are often notched posteriorly. The endophragm is rhomboidal, generally separated from the periphragm by a narrow pericoel. Both wall layers are thin and smooth. The processes are small (up to 3 llm in length), and reach their maximum development at the tip of the horns. They are aligned along the parasutures, with a single row of processes on the paracingular area (see Plate 7, fig. 6). Paratabulation formula: 4", 3a, 7", Xc, 5""", 2"""". The paratabulation style of the dorsal epicystal surface is quadra. The archeopyle is elongated, with rounded corners and narrows anteriorly. The perioperculum is adnate apically, and is enlarged laterally, incorporating the processes corresponding to parasutures la/2a and 2a/3a (Plate 1, fig. 6). The endoperculum is free (entirely surrounded by the archeopyle suture; see Plate 7, fig. 5B). Dimensions. Pericyst. Length: 92 (108) 122 µm. Width: 99 (118) 146 µm. Holotype: 119 x 128 µm. Archeopyle. Length: 22 (26) 30 µm. Width: 22 (25) 28 µm. Holotype: 30 x 24 µm.
Affinities:
Michoux, 1988, p. 36-37: Wetzeliella hampdenensis Wilson is similar to Wetzeliella uncinata in possessing aculeate processes. However, the processes of W. hampdenensis are longer (up to 16 Ám in length, according to Wilson, 1967, p. 481) and are arranged in simulate complexes. In addition, the illustration of the holotype of W. hampdenensis (Wilson, 1967, fig. 19) shows a distinctively quadrate archeopyle with a free operculum.
Originally Wetzeliella, subsequently (and now) Dolichodinium.
Holotype: Michoux, 1988, pl.7, figs.1–5; text-fig.12.
Locus typicus: "Marnes a discocyclines" Louer section, France
Age: early Eocene.
Original diagnosis: Michoux, 1988, p. 36
Circumcavate to cornucavate peridinioid cyst, rhomboidal in outline, strongly compressed dorso-ventrally. Periphragm bears short, hook-like, possibly sutural processes. Archeopyle intercalary (I/2a). Perioperculum elongated, narrowing and adnate anteriorly; endoperculum free.
Original description: Michoux, 1988, p. 36
The cyst is rhomboidal in outline, with four well developed horns: one apical, two lateral and one (left) antapical; the right antapical horn is strongly reduced. The apical and antapical horns taper distally, while the lateral horns are rounded to square-ended, and of variable length. Their distal ends are often notched posteriorly. The endophragm is rhomboidal, generally separated from the periphragm by a narrow pericoel. Both wall layers are thin and smooth. The processes are small (up to 3 llm in length), and reach their maximum development at the tip of the horns. They are aligned along the parasutures, with a single row of processes on the paracingular area (see Plate 7, fig. 6). Paratabulation formula: 4", 3a, 7", Xc, 5""", 2"""". The paratabulation style of the dorsal epicystal surface is quadra. The archeopyle is elongated, with rounded corners and narrows anteriorly. The perioperculum is adnate apically, and is enlarged laterally, incorporating the processes corresponding to parasutures la/2a and 2a/3a (Plate 1, fig. 6). The endoperculum is free (entirely surrounded by the archeopyle suture; see Plate 7, fig. 5B). Dimensions. Pericyst. Length: 92 (108) 122 µm. Width: 99 (118) 146 µm. Holotype: 119 x 128 µm. Archeopyle. Length: 22 (26) 30 µm. Width: 22 (25) 28 µm. Holotype: 30 x 24 µm.
Affinities:
Michoux, 1988, p. 36-37: Wetzeliella hampdenensis Wilson is similar to Wetzeliella uncinata in possessing aculeate processes. However, the processes of W. hampdenensis are longer (up to 16 Ám in length, according to Wilson, 1967, p. 481) and are arranged in simulate complexes. In addition, the illustration of the holotype of W. hampdenensis (Wilson, 1967, fig. 19) shows a distinctively quadrate archeopyle with a free operculum.