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Gochteodinia mutabilis
Gochteodinia mutabilis (Riley in Fisher and Riley, 1980, p.324-325, pl.3, figs.1-3) Fisher and Riley, 1982 (July), p.53. Emendation: Below, 1990, p.49, as Gochteodinia mutabilis.
Originally Pareodinia, subsequently (and now) Gochteodinia. Davey (1982b, p.24; dated July 30th) also proposed this combination. Gochteodinia mutabilis was not validly published in Fisher and Riley (1976, p.52), since no description or illustration was provided.
Holotype: Gitmez and Sarjeant, 1972, pl.11, fig.1.
Age: Volgian.
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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.
Gochteodinia mutabilis (Riley in Fisher and Riley, 1980) Fisher and Riley, 1982, is elongate ovoidal, with a strong apical horn, typically terminating in a thread-like apicular structure of variable length. Epitract and hypotract of about equal size with little or no cingular trace. No obvious tabulation. Archeopyle type 2I. Cyst wall smooth to densely granular, bearing numerous, irregularly distributed processes of variable form; slender, short, simple spine-like projections to very irregular, knobbly and frequently branched or capitate structures. Size: overall length 50-87 µm, width 25-43 µm, length of apical horn 4-13 µm, length of apicular thread 4-13 µm, length of surface processes 2-8 µm.
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Original diagnosis: Riley, 1980, p. 324: Pareodinia mutabilis
Cyst elongate ovoidal, bearing a strong apical horn, typically terminating in a thread-like apicular structure of variable length. Epitract and hypotract approximately equal with little or no cingular trace. Reflected paratabulation other than cingular trace, archaeopyle outline and operculum not evident. Archaeopyle intercalary, type 2I. Cyst wall smooth to densely granular, bearing numerous, irregularly distributed processes of variable form: slender, short, simple spine-like projections to very irregularly knobbly and frequently branched or capitate structures.
Dimensions: Overall length 50-87 Ám; breadth: 25-43 Ám; length of apical horn: 11 Ám; length of apical thread: 3-11 Ám; length of surface processes: 2-8 Ám.
Emended description: Below, 1990, p. 49
Vesicle/plate arrangement on amphiesma cop, pop, cap, 3', 2a, 6'', 7c, 6''', 2'''', as, FM, ls, rs, ps; 1' exsert, 1a and 2a pentagonal. Growth of thecal plates gonyaulacoid. Cyst proximate, acavate-cornucavate, cylindrical to flask-shaped, epicyst streched into long apical horn, antapex blunt, rounded or rarely dented between two antapical bulges, epicyst twice as long as hypocyst, maximal cross-section at posterior cingular margin, equatorial section circular; wall consists of thin pedium and granular-prismatic luxuria, surface finely granulate and loosely to densely covered with crispae, varying in length, nonareate except for the archaeopyle-sutures; paratabulation XPR, NR', 1a(arch)-2a(arch), NR'', NRc/Xc, NR''', NR'''', NRs; penta 1a (DDL) and 2a (DR), anteriorly geniculate 2'' (L), 4'' (DDR) and 5'' (R), anteriorly linear 3'' (DDL); archaeopyle anterior intercalary, 1a+2a; operculum solvate, opercular plates secate, general opercular formula 1a(s)+2a(s).
Poulsen 1996 p. 61 Pl. 5, Figs. 5-6: Gochteodinia mutabilis (Riley 1980) Davey 1982
Remarks. The Danish and Polish specimens of G. mutabilis conform to the descriptions of Gitmez and Sarjeant (1972, p. 233), Riley (1980), and Davey (1982) in their diagnostic features (granulate, verrucate to spinose ornament, 2I archeopyle). However, granulate to verrucate specimens do certainly suggest the genus Pareodinia to which Riley (1980) attributed this species. It may be interpreted as a transitional form between Pareodinia and Gochteodinia. The apicular structure is often missing and cannot be regarded as particularly diagnostic (Wiggins, 1975).
Recorded occurrences. Denmark: Glossodinium dimorphum Zone, Subzone c Dichadogonyaulax culmula Zone, Subzone a. Poland: Tenuicostatum - Scythicus Zone.
Originally Pareodinia, subsequently (and now) Gochteodinia. Davey (1982b, p.24; dated July 30th) also proposed this combination. Gochteodinia mutabilis was not validly published in Fisher and Riley (1976, p.52), since no description or illustration was provided.
Holotype: Gitmez and Sarjeant, 1972, pl.11, fig.1.
Age: Volgian.
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Gochteodinia mutabilis (Riley in Fisher and Riley, 1980) Fisher and Riley, 1982, is elongate ovoidal, with a strong apical horn, typically terminating in a thread-like apicular structure of variable length. Epitract and hypotract of about equal size with little or no cingular trace. No obvious tabulation. Archeopyle type 2I. Cyst wall smooth to densely granular, bearing numerous, irregularly distributed processes of variable form; slender, short, simple spine-like projections to very irregular, knobbly and frequently branched or capitate structures. Size: overall length 50-87 µm, width 25-43 µm, length of apical horn 4-13 µm, length of apicular thread 4-13 µm, length of surface processes 2-8 µm.
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Original diagnosis: Riley, 1980, p. 324: Pareodinia mutabilis
Cyst elongate ovoidal, bearing a strong apical horn, typically terminating in a thread-like apicular structure of variable length. Epitract and hypotract approximately equal with little or no cingular trace. Reflected paratabulation other than cingular trace, archaeopyle outline and operculum not evident. Archaeopyle intercalary, type 2I. Cyst wall smooth to densely granular, bearing numerous, irregularly distributed processes of variable form: slender, short, simple spine-like projections to very irregularly knobbly and frequently branched or capitate structures.
Dimensions: Overall length 50-87 Ám; breadth: 25-43 Ám; length of apical horn: 11 Ám; length of apical thread: 3-11 Ám; length of surface processes: 2-8 Ám.
Emended description: Below, 1990, p. 49
Vesicle/plate arrangement on amphiesma cop, pop, cap, 3', 2a, 6'', 7c, 6''', 2'''', as, FM, ls, rs, ps; 1' exsert, 1a and 2a pentagonal. Growth of thecal plates gonyaulacoid. Cyst proximate, acavate-cornucavate, cylindrical to flask-shaped, epicyst streched into long apical horn, antapex blunt, rounded or rarely dented between two antapical bulges, epicyst twice as long as hypocyst, maximal cross-section at posterior cingular margin, equatorial section circular; wall consists of thin pedium and granular-prismatic luxuria, surface finely granulate and loosely to densely covered with crispae, varying in length, nonareate except for the archaeopyle-sutures; paratabulation XPR, NR', 1a(arch)-2a(arch), NR'', NRc/Xc, NR''', NR'''', NRs; penta 1a (DDL) and 2a (DR), anteriorly geniculate 2'' (L), 4'' (DDR) and 5'' (R), anteriorly linear 3'' (DDL); archaeopyle anterior intercalary, 1a+2a; operculum solvate, opercular plates secate, general opercular formula 1a(s)+2a(s).
Poulsen 1996 p. 61 Pl. 5, Figs. 5-6: Gochteodinia mutabilis (Riley 1980) Davey 1982
Remarks. The Danish and Polish specimens of G. mutabilis conform to the descriptions of Gitmez and Sarjeant (1972, p. 233), Riley (1980), and Davey (1982) in their diagnostic features (granulate, verrucate to spinose ornament, 2I archeopyle). However, granulate to verrucate specimens do certainly suggest the genus Pareodinia to which Riley (1980) attributed this species. It may be interpreted as a transitional form between Pareodinia and Gochteodinia. The apicular structure is often missing and cannot be regarded as particularly diagnostic (Wiggins, 1975).
Recorded occurrences. Denmark: Glossodinium dimorphum Zone, Subzone c Dichadogonyaulax culmula Zone, Subzone a. Poland: Tenuicostatum - Scythicus Zone.