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Oligosphaeridium patulum
Oligosphaeridium patulum Riding and Thomas, 1988
Holotype: Riding and Thomas, 1988, pl.3, figs.1-2
Paratypes: Riding and Thomas, 1988
Locus typicus Norfolk, England
Stratum typicum: Late Kimmeridgian
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Oligosphaeridium patulum Riding and Thomas, 1988. According to Riding and Thomas (1988, p.80-81), this is a skolochorate dinocyst, with a spherical to subspherical body. Autophragm smooth to finely granulate. Paratabulation gonyaulacacean, indicated by intratabular (plate-centred) processes. Kofoidian process formula 4', 6", 0c, 5-6"’, 1p, 1"”. Paracingular and parasulcal processes entirely lacking. Processes tubiform, open and widely expanded distally. Process tips deeply multifurcate, producing an irregularly digitate distal opening; fenestrae occasionally to frequently developed. Archeopyle apical (4A), operculum free. Size: overall 79.2-110.4 µm, diameter of central body 40.8-64.8 µm, length of processes 19.2-38.4 µm, proximal width of processes 2.4-7.2 µm, distal width of processes (not including apicals) 19.2-38.4 µm, distal width of apical processes 11.8-15.7 µm
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Original diagnosis: Riding and Thomas, 1988, p. 80-81
Skolochorate dinoflagellate cysts, cyst body spherical to subspherical in shape. Autophragm smooth to finely granulate. Paratabulation gonyaulacacean, indicated by intratabular (paraplate-centered) processes. Kofoidian process formula: 4', 6", 0c, 5-6''', Ip, 1''''. Paracingular and parasutural processes entirely lacking. Processes tubiform, open and widely expanded distally. Process tips deeply multifurcate, producing an irregularly digitate distal opening; fenestrae occasionally to frequently developed. Archeopyle apical, type (4A), operculum free.
Original description: Riding and Thomas, 1988, p. 81
A species of Oligosphaeridium with a moderately thick-walled, smooth to finely granulate cyst body. It bears stout, robust, tubiform, paraplate-centered processes. The processes are open and markedly expanded distally, thus imparting a subtriangular outline; they are deeply distally multifurcate; branching occurs at up to 70% of the entire process length. The distal process margins are consequently irregularly digitate. Individually, interconnections or trabeculae between branchesmay be developed, imparting a fenestrate pattern to areas of the branching process. The four apical processes tend to be consistently more slender than the processes on the loisthocyst.
Poulsen, 1996, p. 69
Oligosphaeridium aff. O. patulum Riding and Thomas 1988
Pl. 29, Fig. 2
Remarks. This form has large tubiform processes which are open and expanded distally with a digitate, highly irregular margin as in O. patulum; however, this form has distinct ring trabeculae, which terminate the processes distally. This form may be transitional between Oligosphaeridium species and Stiphrosphaeridium species.
Recorded occurrence. Poland: Isterites Horizon above Tenuicostatum Zone.
Holotype: Riding and Thomas, 1988, pl.3, figs.1-2
Paratypes: Riding and Thomas, 1988
Locus typicus Norfolk, England
Stratum typicum: Late Kimmeridgian
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Oligosphaeridium patulum Riding and Thomas, 1988. According to Riding and Thomas (1988, p.80-81), this is a skolochorate dinocyst, with a spherical to subspherical body. Autophragm smooth to finely granulate. Paratabulation gonyaulacacean, indicated by intratabular (plate-centred) processes. Kofoidian process formula 4', 6", 0c, 5-6"’, 1p, 1"”. Paracingular and parasulcal processes entirely lacking. Processes tubiform, open and widely expanded distally. Process tips deeply multifurcate, producing an irregularly digitate distal opening; fenestrae occasionally to frequently developed. Archeopyle apical (4A), operculum free. Size: overall 79.2-110.4 µm, diameter of central body 40.8-64.8 µm, length of processes 19.2-38.4 µm, proximal width of processes 2.4-7.2 µm, distal width of processes (not including apicals) 19.2-38.4 µm, distal width of apical processes 11.8-15.7 µm
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Original diagnosis: Riding and Thomas, 1988, p. 80-81
Skolochorate dinoflagellate cysts, cyst body spherical to subspherical in shape. Autophragm smooth to finely granulate. Paratabulation gonyaulacacean, indicated by intratabular (paraplate-centered) processes. Kofoidian process formula: 4', 6", 0c, 5-6''', Ip, 1''''. Paracingular and parasutural processes entirely lacking. Processes tubiform, open and widely expanded distally. Process tips deeply multifurcate, producing an irregularly digitate distal opening; fenestrae occasionally to frequently developed. Archeopyle apical, type (4A), operculum free.
Original description: Riding and Thomas, 1988, p. 81
A species of Oligosphaeridium with a moderately thick-walled, smooth to finely granulate cyst body. It bears stout, robust, tubiform, paraplate-centered processes. The processes are open and markedly expanded distally, thus imparting a subtriangular outline; they are deeply distally multifurcate; branching occurs at up to 70% of the entire process length. The distal process margins are consequently irregularly digitate. Individually, interconnections or trabeculae between branchesmay be developed, imparting a fenestrate pattern to areas of the branching process. The four apical processes tend to be consistently more slender than the processes on the loisthocyst.
Poulsen, 1996, p. 69
Oligosphaeridium aff. O. patulum Riding and Thomas 1988
Pl. 29, Fig. 2
Remarks. This form has large tubiform processes which are open and expanded distally with a digitate, highly irregular margin as in O. patulum; however, this form has distinct ring trabeculae, which terminate the processes distally. This form may be transitional between Oligosphaeridium species and Stiphrosphaeridium species.
Recorded occurrence. Poland: Isterites Horizon above Tenuicostatum Zone.