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Atopodinium haromense
Atopodinium haromense, Thomas and Cox, 1988
Holotype: Thomas and Cox, 1988, pl.1, fig.1-2; text-fig.4; Masure, 1991, pl.1, figs.1-3; text-figs.1a-b
Stratum typicum: Late Oxfordian-Early Kimmeridgian
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Original description: [Thomas and Cox, 1988, p.319-321, 323]:
Diagnosis:
proximate cysts, rounded polygonal to sharply polygonal in outline, generally six-sided and found in dorso-ventral compression. The autophragm is scabrate to finely granulate. The paratabulation is often obscure, the parasutures being marked by irregular rows of grana and gemmae or by folds. The paracingulum and parasulcus are prominent features generally evidient as strong equatorial and longitudinal folds respectively. The paratabulation appears to conform to a gonyaulacoid pattern and is marked on the epicyst by the position of the accessory archaeopyle sutures. Paraplate 1'''' is more densely granulate than the rest of the cyst and imparts a flattened or convex shape to the antapex.
The archaeopyle is of apical type (tA).
Dimensions:
Length (apex intact) 61 (av.76) 88 µm; Width 57 (av.68) 78 µm (6 specimens measured).
Affinities:
Atopodinium haromense differs from A. prostatum Drugg 1978 in lacking prominent lobes at the antapex. The antapical paraplate of A. haromense is flat or convex, not deeply invaginated. In other respects, the morphology is very similar to that of A. prostatum.
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Modified description:
Masure, 1991, p.65-66:
Description:
Slightly dorsoventrally compressed, subspheroidal, acavate, proximate dinocyst. A sexiform gonyaulacoid thecal tabulation is inferred. Paratabulation is incompletely delineated by penitabular rows of grana or gemmae and folds. These elements of relief suggest that the paratabulation is composed of ?0-2 preapical(s) (P,Q), 1 anterior intercalary (K) 4 apicals (1u,B,C,A), 6 precingulars (1i, 2-6), X cingulars, 5-?6 postcingulars (?Iu, II-VI), ?1 posterior intercalary (X), 1 antapical (Y), and X sulcals. The apical ornamentation is weakly expressed. Penitabular adcingular rows of grana or gemmae mark the edges of the precingular paraplates. Two rows of grana or gemmae mark the descending paracingulum. The ventral area is untabulated. The sulcal paraplates and the parasutures between the sulcus and the precingular (2, 1i), postcingular (Iu, II, VI) and posterior intercalary (X) paraplates are not expressed by surface features. Only four postcingular parasutures (II/III, III/IV, IV/V, V/VI) are expressed by penitabular ornament of adjacent paraplates in close contact with one another. The postcingular 4 is below precingular 4, and the postcingular parasuture IV/V is aligned with the precingular 4/5. The antapical paraplate Y is more densely granulate than the rest of the cyst, invaginated Y imparts flattened shape to the antapex outline, and devaginated Y convex, rounded antapex. The apical archeopyle is of (tA)a type, with precingular accessory parasutures. The simple, polyplacoid operculum is adnate to the sulcal ai, and precingular 2 and 1i paraplates.
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Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Atopodinium haromense Thomas and Cox, 1988. Diagnosis from Thomas and Cox (1988, P.319-321): Proximate cysts, rounded polygonal to sharply polygonal in outline, generally six-sided and found in dorso-ventral compression. The autophragm is scabrate to finely granulate. Paratabulation often obscure. Parasutures marked by irregular rows of grana and gemmae or folds. Paracingulum and parasulcus prominent. Paraplate 1"” more granulate than other plates and imparts a flattened or convex shape to the antapex. Archeopyle apical with accessory sutures. It differs from A. prostatum in lacking prominent lobes at the antapex. Masure (1991, p.65-66) provided a modified description for this species. Ornamentation suggests tabulation of 0-2 preapicals, 1 as, 4', 6", xc, 5-?6"’, 1p, 1"”, xs. Penitabular adcingular rows of grana or gemmae mark the edges of the precingular plates. The paracingulum is delineated by two rows of grana or gemmae. Postcingular 4"’ is below 3". Operculum adnate. Size: length 61-88 µm, width 57-78 µm.
Holotype: Thomas and Cox, 1988, pl.1, fig.1-2; text-fig.4; Masure, 1991, pl.1, figs.1-3; text-figs.1a-b
Stratum typicum: Late Oxfordian-Early Kimmeridgian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Thomas and Cox, 1988, p.319-321, 323]:
Diagnosis:
proximate cysts, rounded polygonal to sharply polygonal in outline, generally six-sided and found in dorso-ventral compression. The autophragm is scabrate to finely granulate. The paratabulation is often obscure, the parasutures being marked by irregular rows of grana and gemmae or by folds. The paracingulum and parasulcus are prominent features generally evidient as strong equatorial and longitudinal folds respectively. The paratabulation appears to conform to a gonyaulacoid pattern and is marked on the epicyst by the position of the accessory archaeopyle sutures. Paraplate 1'''' is more densely granulate than the rest of the cyst and imparts a flattened or convex shape to the antapex.
The archaeopyle is of apical type (tA).
Dimensions:
Length (apex intact) 61 (av.76) 88 µm; Width 57 (av.68) 78 µm (6 specimens measured).
Affinities:
Atopodinium haromense differs from A. prostatum Drugg 1978 in lacking prominent lobes at the antapex. The antapical paraplate of A. haromense is flat or convex, not deeply invaginated. In other respects, the morphology is very similar to that of A. prostatum.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Modified description:
Masure, 1991, p.65-66:
Description:
Slightly dorsoventrally compressed, subspheroidal, acavate, proximate dinocyst. A sexiform gonyaulacoid thecal tabulation is inferred. Paratabulation is incompletely delineated by penitabular rows of grana or gemmae and folds. These elements of relief suggest that the paratabulation is composed of ?0-2 preapical(s) (P,Q), 1 anterior intercalary (K) 4 apicals (1u,B,C,A), 6 precingulars (1i, 2-6), X cingulars, 5-?6 postcingulars (?Iu, II-VI), ?1 posterior intercalary (X), 1 antapical (Y), and X sulcals. The apical ornamentation is weakly expressed. Penitabular adcingular rows of grana or gemmae mark the edges of the precingular paraplates. Two rows of grana or gemmae mark the descending paracingulum. The ventral area is untabulated. The sulcal paraplates and the parasutures between the sulcus and the precingular (2, 1i), postcingular (Iu, II, VI) and posterior intercalary (X) paraplates are not expressed by surface features. Only four postcingular parasutures (II/III, III/IV, IV/V, V/VI) are expressed by penitabular ornament of adjacent paraplates in close contact with one another. The postcingular 4 is below precingular 4, and the postcingular parasuture IV/V is aligned with the precingular 4/5. The antapical paraplate Y is more densely granulate than the rest of the cyst, invaginated Y imparts flattened shape to the antapex outline, and devaginated Y convex, rounded antapex. The apical archeopyle is of (tA)a type, with precingular accessory parasutures. The simple, polyplacoid operculum is adnate to the sulcal ai, and precingular 2 and 1i paraplates.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Atopodinium haromense Thomas and Cox, 1988. Diagnosis from Thomas and Cox (1988, P.319-321): Proximate cysts, rounded polygonal to sharply polygonal in outline, generally six-sided and found in dorso-ventral compression. The autophragm is scabrate to finely granulate. Paratabulation often obscure. Parasutures marked by irregular rows of grana and gemmae or folds. Paracingulum and parasulcus prominent. Paraplate 1"” more granulate than other plates and imparts a flattened or convex shape to the antapex. Archeopyle apical with accessory sutures. It differs from A. prostatum in lacking prominent lobes at the antapex. Masure (1991, p.65-66) provided a modified description for this species. Ornamentation suggests tabulation of 0-2 preapicals, 1 as, 4', 6", xc, 5-?6"’, 1p, 1"”, xs. Penitabular adcingular rows of grana or gemmae mark the edges of the precingular plates. The paracingulum is delineated by two rows of grana or gemmae. Postcingular 4"’ is below 3". Operculum adnate. Size: length 61-88 µm, width 57-78 µm.