Back
Kaiwaradinium ramosum
Kaiwaradinium ramosum Wilson, 1984
Holotype: Wilson, 1984a, figs.12A-B,16-17; Fensome et al., 1996, figs.1-2,7-8 - p.2315; Fauconnier and Masure, 2004, pl.50, fig.8
Locus typicus: Kaiwara Valley, N Canterbury, New Zealand
Stratum typicum: Puaroan, Early Tithonian
Age: Valanginian, according to Wilson and Helby (1988).
Original diagnosis: Wilson, 1984, p.217, 219
A Kaiwaradirlium with a large ovoidal central body (length/breadth ratio approximately 2:1). Periphragm and endophragm both reticulate. Processes typically numbering 17, somewhat fibrous. hollow, with prominent irregularly branched tips. Large central area devoid of processes. Archeopyle broad with prominent parasulcal notch; operculum free and bearing four relatively small processes.
Dimensions: Holotype: overall length (without operculum) 165 Ám, breadth 140 Ám; length of endocyst 105 Ám, breadth 70 Ám; length of processes 27-59 Ám, breadth of processes (proximal) 4-16 Ám. Range of 10 specimens (all without operculum): overall length 124 (142) 165 Ám, breadth 108 (123) 140 Ám; length of endocyst 86 (99) 108 Ám, breadth 54 (61) 73 Ám.
Original description: Wilson, 1984, p.219
The periphragm is thin (up to 1 Ám) and finely reticulate (lacunae about 1 Ám). The endophragm is fairly thin (1-2 Ám) and very finely reticulate; it is closely appressed to the periphragm between processes. The hollow, fibrous processes are formed only from the periphragm, are open distally, and the distal parts are characteristically branched into several thin filaments. The dorsal postcingular and antapical processes are the broadest processes and the ventral processes the narrowest; the apical processes are relatively short. A slender, relatively short posterior intercalary process is constantly present. The archeopyle has a zig-zag margin with a deep parasulcal notch. The central part of the cyst is devoid of processes and usually shows no clear indication of a paracingulum, although in some specimens a faint paracingulum may be indicated by alignments of the periphragm reticulum. The anterior position of the parasulcus is indicated by the parasulcal notch.
Affinities:
Wilson, 1984, p.221: Kaiwaradinium ramosum is readily distinguished from the type species, K. buccinatum Wilson, by the characteristically branched process tips. Specimens with an intact operculum are extremely rare.
Holotype: Wilson, 1984a, figs.12A-B,16-17; Fensome et al., 1996, figs.1-2,7-8 - p.2315; Fauconnier and Masure, 2004, pl.50, fig.8
Locus typicus: Kaiwara Valley, N Canterbury, New Zealand
Stratum typicum: Puaroan, Early Tithonian
Age: Valanginian, according to Wilson and Helby (1988).
Original diagnosis: Wilson, 1984, p.217, 219
A Kaiwaradirlium with a large ovoidal central body (length/breadth ratio approximately 2:1). Periphragm and endophragm both reticulate. Processes typically numbering 17, somewhat fibrous. hollow, with prominent irregularly branched tips. Large central area devoid of processes. Archeopyle broad with prominent parasulcal notch; operculum free and bearing four relatively small processes.
Dimensions: Holotype: overall length (without operculum) 165 Ám, breadth 140 Ám; length of endocyst 105 Ám, breadth 70 Ám; length of processes 27-59 Ám, breadth of processes (proximal) 4-16 Ám. Range of 10 specimens (all without operculum): overall length 124 (142) 165 Ám, breadth 108 (123) 140 Ám; length of endocyst 86 (99) 108 Ám, breadth 54 (61) 73 Ám.
Original description: Wilson, 1984, p.219
The periphragm is thin (up to 1 Ám) and finely reticulate (lacunae about 1 Ám). The endophragm is fairly thin (1-2 Ám) and very finely reticulate; it is closely appressed to the periphragm between processes. The hollow, fibrous processes are formed only from the periphragm, are open distally, and the distal parts are characteristically branched into several thin filaments. The dorsal postcingular and antapical processes are the broadest processes and the ventral processes the narrowest; the apical processes are relatively short. A slender, relatively short posterior intercalary process is constantly present. The archeopyle has a zig-zag margin with a deep parasulcal notch. The central part of the cyst is devoid of processes and usually shows no clear indication of a paracingulum, although in some specimens a faint paracingulum may be indicated by alignments of the periphragm reticulum. The anterior position of the parasulcus is indicated by the parasulcal notch.
Affinities:
Wilson, 1984, p.221: Kaiwaradinium ramosum is readily distinguished from the type species, K. buccinatum Wilson, by the characteristically branched process tips. Specimens with an intact operculum are extremely rare.