Back
Pseudoceratium polymorphum
Pseudoceratium polymorphum (Eisenack, 1958a, p.394, pl.22, figs.5–12; pl.24, fig.5) Bint, 1986, p.145. Emendation: Dörhöfer and Davies, 1980, p.34–36, as Aptea polymorpha.
NOW Aptea. Originally (and now) Aptea, subsequently Pseudoceratium. By retaining Aptea, Quattrocchio and Sarjeant (1992, p.2–234) effectively retained Aptea polymorpha, the "type species", as a species of Aptea.
Taxonomic junior synonym: Aptea (now Pseudoceratium) eisenackii, according to Cookson and Eisenack (1974, p.74) — however, Below (1981a, p.7) retained Aptea eisenackii.
Holotype: Eisenack, 1958, pl.22, fig.5; Sarjeant, 1985, pl.7, fig.4
Locus typicus: Marne, Feld Heide, Holstein, N Germany
Stratum typicum: Early Cretaceous
Translation Eisenack, 1958: LPP
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Aptea polymorpha Eisenack, 1958a, emend. Dörhöfer and Davies, 1980. From Eisenack, 1958, this has a flat autocyst, irregularly triangular in outline with convex sides and indistinctly affixed horns. The surface has an irregularly developed, low ledgework that forms a more or less fine-meshed, though indistinct honey-comb pattern. In an approximately radial direction, the ledges encroach upon the delicate and unequally wide membrane, the distal margins of which rarely form a smooth line, but seem frequently jagged and fimbriate. Of the three poorly developed horns, all except one may be more or less rudimentary. Dörhöfer and Davies (1980, p.34-36) gave a tabulation of 4', 2a, 6", 5-6c, 6"’, 1p, 1"”, 3-06s Length 80-120 µm.
--------------------------------------------------
Original description: Eisenack, 1958, p. 394: Aptea polymorpha
Diagnosis: Body (apparently naturally) flattened, in outline irregularly triangular with convex sides and indistinctly offset "horns", consisting of a rounded and dark inner capsule, which is ringed in by a more or less complete fringe. The surface is ornamented with an irregularly shaped network of low ridges, which forms a more or less fine, indistinct meshwork. In a radial direction, the ridges pass into the delicate, unequally thick edge, the margins of which rarely form a smooth line, but often appear zigzag and raveled. The 3 (also 4?) indistinctly developed horns can all but one be totally reduced.
Dimensions: Length: 80-120 Ám; Mean: 101 Ám; 20 specimens measured. Holotype: 114:80 Ám.
Emended description (annotated): D÷rh÷fer and Davies, 1980, p. 34-36: Aptea polymorpha
Autoblast subcircular to egg-shaped in outline, dorsoventrally flattened. Slight outward bulging occurs sometimes in the position of the three (occasionally four) horns which are marked by ornamental differentiation. These positions correspond to apical (left), antapical, and right postcingular horns. Either or both of the latter may not be developed, the postcingular being suppressed first. The axis connecting the apical and antapical horns is always shifted to the left, the cyst being always asymmetrical. The autoblast is rather thick-walled. Its surface is finely pitted to granulate. Often sutures are marked by relatively broad pandasutural zones, representing intercalary growth bands, characterized by striations perpendicular to the plate boundaries. Pandasutural areas are particularly distinct on the epitract along the archaeopyle suture, less so on the hypotract. Tabulation 4', 2a, 6'', 5-6c, 6''', 1p, 1'''', ?3-6s. Ornamentation on cingular, sulcal and 6c and 6'' plates may be reduced or absent. 1p and 1p/1''' boundary may be indistinct. Sulcal area consist of anterior, posterior and left sulcal plates, accessory plates may be faintly indidcated. Position of flagellar pore indicated by ring of low ridges left of the anterior sulcal plate. Ornamentation variable, consisting of broadly based, tapered and distally widened baculae, 5-15 Ám in height, and frequently fusing distally. Horns up to 30 Ám. Ornamentation in apical and antapical region appressed and subparallel to autophragm. The angle between right postcingular horn and length-axis of the cyst becomes smaller as the cyst becomes longer, and disappears at a length-width ratio of 1.6; shorter cysts, on the other hand, may show development of a left postcingular horn. In this case, the positions of the postcingular bulges become harder to determine, and the cyst outline becomes subcircular. Archaeopyle (4A2I); its zigzag suture is asymmetrical, the left part being strongly deflected to the apex, the right part to the cingulum. Ventrally a sulcal notch is developed between 1'' and 6'', another where 5'' and 6'' meet at the archaeopyle suture. Dorsally the suture dips at the junctions of 2'/2''/3'' and of 3'/3''/4''. The presence of intercalary plates causes the asymmetry of the archaeopyle suture and of the autoblast. Sutures between apicaland intercalay plates are very faint.
NOW Aptea. Originally (and now) Aptea, subsequently Pseudoceratium. By retaining Aptea, Quattrocchio and Sarjeant (1992, p.2–234) effectively retained Aptea polymorpha, the "type species", as a species of Aptea.
Taxonomic junior synonym: Aptea (now Pseudoceratium) eisenackii, according to Cookson and Eisenack (1974, p.74) — however, Below (1981a, p.7) retained Aptea eisenackii.
Holotype: Eisenack, 1958, pl.22, fig.5; Sarjeant, 1985, pl.7, fig.4
Locus typicus: Marne, Feld Heide, Holstein, N Germany
Stratum typicum: Early Cretaceous
Translation Eisenack, 1958: LPP
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Aptea polymorpha Eisenack, 1958a, emend. Dörhöfer and Davies, 1980. From Eisenack, 1958, this has a flat autocyst, irregularly triangular in outline with convex sides and indistinctly affixed horns. The surface has an irregularly developed, low ledgework that forms a more or less fine-meshed, though indistinct honey-comb pattern. In an approximately radial direction, the ledges encroach upon the delicate and unequally wide membrane, the distal margins of which rarely form a smooth line, but seem frequently jagged and fimbriate. Of the three poorly developed horns, all except one may be more or less rudimentary. Dörhöfer and Davies (1980, p.34-36) gave a tabulation of 4', 2a, 6", 5-6c, 6"’, 1p, 1"”, 3-06s Length 80-120 µm.
--------------------------------------------------
Original description: Eisenack, 1958, p. 394: Aptea polymorpha
Diagnosis: Body (apparently naturally) flattened, in outline irregularly triangular with convex sides and indistinctly offset "horns", consisting of a rounded and dark inner capsule, which is ringed in by a more or less complete fringe. The surface is ornamented with an irregularly shaped network of low ridges, which forms a more or less fine, indistinct meshwork. In a radial direction, the ridges pass into the delicate, unequally thick edge, the margins of which rarely form a smooth line, but often appear zigzag and raveled. The 3 (also 4?) indistinctly developed horns can all but one be totally reduced.
Dimensions: Length: 80-120 Ám; Mean: 101 Ám; 20 specimens measured. Holotype: 114:80 Ám.
Emended description (annotated): D÷rh÷fer and Davies, 1980, p. 34-36: Aptea polymorpha
Autoblast subcircular to egg-shaped in outline, dorsoventrally flattened. Slight outward bulging occurs sometimes in the position of the three (occasionally four) horns which are marked by ornamental differentiation. These positions correspond to apical (left), antapical, and right postcingular horns. Either or both of the latter may not be developed, the postcingular being suppressed first. The axis connecting the apical and antapical horns is always shifted to the left, the cyst being always asymmetrical. The autoblast is rather thick-walled. Its surface is finely pitted to granulate. Often sutures are marked by relatively broad pandasutural zones, representing intercalary growth bands, characterized by striations perpendicular to the plate boundaries. Pandasutural areas are particularly distinct on the epitract along the archaeopyle suture, less so on the hypotract. Tabulation 4', 2a, 6'', 5-6c, 6''', 1p, 1'''', ?3-6s. Ornamentation on cingular, sulcal and 6c and 6'' plates may be reduced or absent. 1p and 1p/1''' boundary may be indistinct. Sulcal area consist of anterior, posterior and left sulcal plates, accessory plates may be faintly indidcated. Position of flagellar pore indicated by ring of low ridges left of the anterior sulcal plate. Ornamentation variable, consisting of broadly based, tapered and distally widened baculae, 5-15 Ám in height, and frequently fusing distally. Horns up to 30 Ám. Ornamentation in apical and antapical region appressed and subparallel to autophragm. The angle between right postcingular horn and length-axis of the cyst becomes smaller as the cyst becomes longer, and disappears at a length-width ratio of 1.6; shorter cysts, on the other hand, may show development of a left postcingular horn. In this case, the positions of the postcingular bulges become harder to determine, and the cyst outline becomes subcircular. Archaeopyle (4A2I); its zigzag suture is asymmetrical, the left part being strongly deflected to the apex, the right part to the cingulum. Ventrally a sulcal notch is developed between 1'' and 6'', another where 5'' and 6'' meet at the archaeopyle suture. Dorsally the suture dips at the junctions of 2'/2''/3'' and of 3'/3''/4''. The presence of intercalary plates causes the asymmetry of the archaeopyle suture and of the autoblast. Sutures between apicaland intercalay plates are very faint.