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Chytroeisphaeridia cerastes
Chytroeisphaeridia cerastes, Davey, 1979
Holotype: Davey 1979d, Plate 2, figs. 8.
Locus typicus: Staffin Shales, Staffin Bay, Skye, northwest Scotland
Stratum typicum: Lower Oxfordian (C. cordatum Zone).
Age: Early Oxfordian
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Original description: [Davey 1979d, p. 212, 214]:
Diagnosis:
The cyst is ovoidal in shape with a rounded hollow apical horn which merges gently into the main part of the cyst; dorso-ventral flattening is minor.
The apparently single layered wall (autophragm) is typically slightly folded and is of moderate and constant thickness (0.5 µm); it is unstructured internally and smooth externally.
A simple pre-cingular archaeopyle is present formed by the loss of one paraplate (presumably 3").
Lateral and antapical structures and a tabulation are absent.
Description:
Although a tabulation is absent, rarely a minor pitting of the wall does indicate the position of the paracingulum. This pitting may be partly a preservation feature.
Dimensions:
Holotype length 85 µm, width 67 µm.
Range, length 72(79)85 µm, width 62(66)76 µm. Number of specimens measured 10.
Remarks:
The most similar species is C. scabrata Pocock 1972, which differs by only having a thickening of the wall in the apical region as opposed to a definite horn.
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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.
Chytroeisphaeridia cerastes Davey, 1979d, is ovoidal with rounded, hollow apical horn which merges gently into main part of cyst. Single wall is 0.5-1um thick and smooth.
Size: length 72-85 µm, width 62-76 µm.
Holotype: Davey 1979d, Plate 2, figs. 8.
Locus typicus: Staffin Shales, Staffin Bay, Skye, northwest Scotland
Stratum typicum: Lower Oxfordian (C. cordatum Zone).
Age: Early Oxfordian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Davey 1979d, p. 212, 214]:
Diagnosis:
The cyst is ovoidal in shape with a rounded hollow apical horn which merges gently into the main part of the cyst; dorso-ventral flattening is minor.
The apparently single layered wall (autophragm) is typically slightly folded and is of moderate and constant thickness (0.5 µm); it is unstructured internally and smooth externally.
A simple pre-cingular archaeopyle is present formed by the loss of one paraplate (presumably 3").
Lateral and antapical structures and a tabulation are absent.
Description:
Although a tabulation is absent, rarely a minor pitting of the wall does indicate the position of the paracingulum. This pitting may be partly a preservation feature.
Dimensions:
Holotype length 85 µm, width 67 µm.
Range, length 72(79)85 µm, width 62(66)76 µm. Number of specimens measured 10.
Remarks:
The most similar species is C. scabrata Pocock 1972, which differs by only having a thickening of the wall in the apical region as opposed to a definite horn.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Chytroeisphaeridia cerastes Davey, 1979d, is ovoidal with rounded, hollow apical horn which merges gently into main part of cyst. Single wall is 0.5-1um thick and smooth.
Size: length 72-85 µm, width 62-76 µm.