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Pseudoceratium anaphrissum
Pseudoceratium anaphrissum (Sarjeant, 1966c, p.206, pl.22, fig.8; pl.23, fig.6; text-fig.55) Bint, 1986, p.145. Emendation: Harding, 1990b, p.17–18, as Pseudoceratium anaphrissum
Originally Doidyx, subsequently Tenua Eisenack, 1958, thirdly Aptea, fourthly (and now) Pseudoceratium.
Holotype: Sarjeant, 1966, pl.22,fig.8; text-fig.55
Locus typicus: West Heslerton, Yorkshire, England
Stratum typicum: Early Barremian
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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.
Pseudoceratium anaphrissum (Sarjeant, 1966b) Bint, 1986, emend. Harding, 1990b. As emended by Harding (1990b, 17-18), Ambitus subpentagonal to pear-shaped. A short blunt apical horn is usually developed. In addition to this horn a left antapical horn is usually present and may be accompanied by a right antapical horn (often expressed only as a lobe). Two lateral bulges or lobes are developed in an immediately postcingular position. Strong dorso-ventral compression. Epicyst generally larger than hypocyst, may be up to twice the length of the latter. Autophragm equal to or greater than 1 µm thick. Pitted “orange-peel”-like surface sculpture. Apteate, intratabular processes which flare proximally and distally, exceptionally up to 15 µm in length. Tabulation pattern suggested by intratabular processes. Although poorly displayed in most specimens, a study of sufficient numbers yields a paratabulation formula of 4', 6", ?6c, 6"’, 1"”, 1p, xs,. 1i is characteristically large with an obscure adcingular boundary. Archeopyle type (4A) involving all four apicals as a free, simple operculum. Archeopyle suture offset to the left with small accessory sutures developed adjacent to main suture in pre- and postcingulars. Paracingulum poorly developed, seen best on dorsal surface where processes are reduced anterior to a line drawn between the pronounced processes on the lateral bulges. Parasulcus poorly defined an area of reduced processes, ai can be discerned. Size: length 120-145 µm, width 105-130 µm, processes 7 µm.
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Original diagnosis: Sarjeant 1966, p. 206-207: Doidyx anaphrissa
A Doidyx having a asymmetrical biconical shell with short, blunt apical horn and with low bump on antapex. Spines simple, capitate or briefly bifurcate. Portion thrown off in archaeopyle formation exceeding one-third of shell length.
Dimensions: Holotype-overall length 105 µm, breadth 118 µm; shell length 110 µm, breadth 102 µm; spines c. 7 µm long. Range of dimensions: overall lengths c. 120-145 µm, breadths c. 105-130 µm.
Original description: Sarjeant 1966, p. 206-207: Doidyx anaphrissa
This species is moderately abundant, some 25 specimens having been encountered; complete shells were infrequent, detached apices and shells lacking an apex being commoner. The shell is approximately club-shaped: its asymmetry is so pronounced that a longitudinal division would leave some 60% on one side, some 40% on the other. The epitract slopes smoothly into the apical horn; the hypotract is surmounted by an antapical bulge of small height and larger amplitude. The surface is very minutely granular. There is a dense cover of short spines, most often capitate, less frequently evexate, oblate, bifid or bifurcate: these sometimes suggest arrangement into lines, but no coherent pattern was determined. An equatorial belt of moderate breadth, corresponding to the cingulum, lacks spines: a sulcus is not distinguishable. The holotype shows fission to form an archaeopyle, which has however, not become detached. Its margin is distinctly
angular, suggesting a tabulation pattern not otherwise indicated.
Emended diagnosis: Harland, 1990, p. 18
Shape: Ambitus sub-pentagonal to pear-shaped. A short blunt apical horn is usually developed. In addition to this horn a left antapical horn is usually present and may be accompanied by a right antapical horn (often expressed only as a lobe). Two lateral bulges or lobes are developed in an immediately postcingular position. Strong dorso-ventral compression. Epicyst generally larger than hypocyst, may be up to twice the length of the latter. Phragma: Autophragm 1 µm thick. Pitted "orange-peel-like surface sculpture. Apteate, intratabular processes which flare proximally and distally, exceptionally up to 15 µm in length.
Paratabulation: Tabulation pattern suggested by intratabular processes. Although poorly displayed in most specimens, a study of sufficient numbers yields a paratabulation formula of: 4', 6", ?6c, 6''', 1'''', lp, xs. Ii is characteristically very large with an obscure adcingular boundary.
Archaeopyle: Type (4A) involving all four apicals as a free, simple operculum. Archaeopyle suture offset to the left with small accessory sutures developed adjacent to main suture in pre- and post-cingulars.
Paracingulum: Poorly developed, seen best on dorsal surface where processes are reduced anterior to a line drawn between the pronounced processes on the lateral bulges.
Parasulcus: Again poorly defined, an area of reduced processes, ai can be discerned.
Dimensions: Length, plus operculum (139) 119 (91) µm. Width (127) 107 (81) µm
Length, less operculum (94) 87 (79) µm. Specimens = 40 (28).
Affinities:
Sarjeant, 1966, p. 207
In its combination of shape, process cover and mode of archaeopyle formation, Doidyx anaphrissa differs from all other described species.
Sarjeant and Stover 1978, p. 51: Aptea anaphrissa
Aptea anaphrissa is similar to A. eisenackii (Davey) Davey and Verdier (1974), but differs in having isolated processes only, rather than a combination of discontinuous crests and laminae with scattered processes.
Harding, 1990, p. 18: This species is restricted to the Hauptblatterton and corresponding facies - presumably being first described from the lateral equivalent of Bed LB1 at West Heslerton (Sarjeant 1966). Reinvestigation of Sarjeant's type material by the present author has shown that no intercalaries are present, Dörhöfer & Davies (1980) emendation of the genus is not accepted.
Originally Doidyx, subsequently Tenua Eisenack, 1958, thirdly Aptea, fourthly (and now) Pseudoceratium.
Holotype: Sarjeant, 1966, pl.22,fig.8; text-fig.55
Locus typicus: West Heslerton, Yorkshire, England
Stratum typicum: Early Barremian
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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.
Pseudoceratium anaphrissum (Sarjeant, 1966b) Bint, 1986, emend. Harding, 1990b. As emended by Harding (1990b, 17-18), Ambitus subpentagonal to pear-shaped. A short blunt apical horn is usually developed. In addition to this horn a left antapical horn is usually present and may be accompanied by a right antapical horn (often expressed only as a lobe). Two lateral bulges or lobes are developed in an immediately postcingular position. Strong dorso-ventral compression. Epicyst generally larger than hypocyst, may be up to twice the length of the latter. Autophragm equal to or greater than 1 µm thick. Pitted “orange-peel”-like surface sculpture. Apteate, intratabular processes which flare proximally and distally, exceptionally up to 15 µm in length. Tabulation pattern suggested by intratabular processes. Although poorly displayed in most specimens, a study of sufficient numbers yields a paratabulation formula of 4', 6", ?6c, 6"’, 1"”, 1p, xs,. 1i is characteristically large with an obscure adcingular boundary. Archeopyle type (4A) involving all four apicals as a free, simple operculum. Archeopyle suture offset to the left with small accessory sutures developed adjacent to main suture in pre- and postcingulars. Paracingulum poorly developed, seen best on dorsal surface where processes are reduced anterior to a line drawn between the pronounced processes on the lateral bulges. Parasulcus poorly defined an area of reduced processes, ai can be discerned. Size: length 120-145 µm, width 105-130 µm, processes 7 µm.
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Original diagnosis: Sarjeant 1966, p. 206-207: Doidyx anaphrissa
A Doidyx having a asymmetrical biconical shell with short, blunt apical horn and with low bump on antapex. Spines simple, capitate or briefly bifurcate. Portion thrown off in archaeopyle formation exceeding one-third of shell length.
Dimensions: Holotype-overall length 105 µm, breadth 118 µm; shell length 110 µm, breadth 102 µm; spines c. 7 µm long. Range of dimensions: overall lengths c. 120-145 µm, breadths c. 105-130 µm.
Original description: Sarjeant 1966, p. 206-207: Doidyx anaphrissa
This species is moderately abundant, some 25 specimens having been encountered; complete shells were infrequent, detached apices and shells lacking an apex being commoner. The shell is approximately club-shaped: its asymmetry is so pronounced that a longitudinal division would leave some 60% on one side, some 40% on the other. The epitract slopes smoothly into the apical horn; the hypotract is surmounted by an antapical bulge of small height and larger amplitude. The surface is very minutely granular. There is a dense cover of short spines, most often capitate, less frequently evexate, oblate, bifid or bifurcate: these sometimes suggest arrangement into lines, but no coherent pattern was determined. An equatorial belt of moderate breadth, corresponding to the cingulum, lacks spines: a sulcus is not distinguishable. The holotype shows fission to form an archaeopyle, which has however, not become detached. Its margin is distinctly
angular, suggesting a tabulation pattern not otherwise indicated.
Emended diagnosis: Harland, 1990, p. 18
Shape: Ambitus sub-pentagonal to pear-shaped. A short blunt apical horn is usually developed. In addition to this horn a left antapical horn is usually present and may be accompanied by a right antapical horn (often expressed only as a lobe). Two lateral bulges or lobes are developed in an immediately postcingular position. Strong dorso-ventral compression. Epicyst generally larger than hypocyst, may be up to twice the length of the latter. Phragma: Autophragm 1 µm thick. Pitted "orange-peel-like surface sculpture. Apteate, intratabular processes which flare proximally and distally, exceptionally up to 15 µm in length.
Paratabulation: Tabulation pattern suggested by intratabular processes. Although poorly displayed in most specimens, a study of sufficient numbers yields a paratabulation formula of: 4', 6", ?6c, 6''', 1'''', lp, xs. Ii is characteristically very large with an obscure adcingular boundary.
Archaeopyle: Type (4A) involving all four apicals as a free, simple operculum. Archaeopyle suture offset to the left with small accessory sutures developed adjacent to main suture in pre- and post-cingulars.
Paracingulum: Poorly developed, seen best on dorsal surface where processes are reduced anterior to a line drawn between the pronounced processes on the lateral bulges.
Parasulcus: Again poorly defined, an area of reduced processes, ai can be discerned.
Dimensions: Length, plus operculum (139) 119 (91) µm. Width (127) 107 (81) µm
Length, less operculum (94) 87 (79) µm. Specimens = 40 (28).
Affinities:
Sarjeant, 1966, p. 207
In its combination of shape, process cover and mode of archaeopyle formation, Doidyx anaphrissa differs from all other described species.
Sarjeant and Stover 1978, p. 51: Aptea anaphrissa
Aptea anaphrissa is similar to A. eisenackii (Davey) Davey and Verdier (1974), but differs in having isolated processes only, rather than a combination of discontinuous crests and laminae with scattered processes.
Harding, 1990, p. 18: This species is restricted to the Hauptblatterton and corresponding facies - presumably being first described from the lateral equivalent of Bed LB1 at West Heslerton (Sarjeant 1966). Reinvestigation of Sarjeant's type material by the present author has shown that no intercalaries are present, Dörhöfer & Davies (1980) emendation of the genus is not accepted.