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Wallodinium cylindricum
From Fensome et al., 2019:
Wallodinium cylindricum (Habib, 1970) Duxbury, 1983; Emendations: Prauss, 1989, p.47–48; Riding, 1994, p.18; Feist-Burkhardt and Monteil, 1994, p.7, all as Wallodinium cylindricum.
Originally Prismatocystis, subsequently Hexagonifera, thirdly (and now) Wallodinium.
Taxonomic junior synonym: Fromea (as Wallodinium, now Phallocysta) elongata, according to Duxbury (1983, p.68) — however, Feist-Burkhardt and Monteil in Feist-Burkhardt (1990, p.615) retained Fromea (as Andreedinium) elongata.
Holotype: Habib, 1970, pl.10, fig.2
Locus typicus: Core RC10-282, near the Horizon Beta deep-sea outcrop, Atlantic
Stratum typicum: Middle Cretaceous
Age: Albian-Cenomanian
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Original description Habib 1970, p. 374: Prismatocystis cylindrica
Prismatic acritarch, with a broadly rounded to subpyramidal closed apex opposite an open truncated apex. Periphragm sides straight or slightly convex.. Endophragm circular in outline, frequently open and folded, its diameter approximately half the length of the periphragm, located near closed apex, thinner (less than one micron in thickness) than periphragm. Periphragm and endophragm psilate.
Remarks: P. cylindrica is distinguished by its rounded apex and size, The endophragm is missing in two of the six specimens.
Occurence: Rare in all cores but RC10-284. Most common in core RC10-282.
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Emended description: Feist-Burkhardt & Monteil 1994, p. 7
Dinoflagellate cyst. Proximate, epicavate, with straight longitudinal axis. Pericyst stocky, subcylindrical with a broadly rounded antapex. Endocyst subspherical, relatively free in the pericyst, and consistently located at antapex when present. Peri- and endophragm psilate. Periarchaeopyle apical, type (tA). Endoarchaeopyle type undetermined. Perioperculum domeshaped, generally free. Endoperculum attached. Paratabulation generally expressed by archaeopyle only. Partial paratabulation formula: 4', 6" + as. Paracingulum may be indicated by a weak constriction situated at about half the cyst length, above top of endocyst. Parasulcus not indicated, except as.
Observed size range: Length of pericyst: 40-43 µm ; width of pericyst: 26-29 µm; length of endocyst: 25-26 µm; width of endocyst: 24-29 µm.
Comparisons: Wallodinium cylindricum n. emend. differs from Prismatocystis ewingii Habib 1969 in having a broadly rounded antapex rather than a pyramidal antapex. W krutzschii (Alberti 1961) Habib 1972 is bicavate to circumcavate, elongate fusiform, with a narrowly rounded to pointed antapex.
Previously reported occurrences: Feist-Burkhardt & Monteil 1994, p. 7
Wallodinium cylindricum was first described from Albian to Cenomanian deep-sea sediments from northeast of the Bahamas. Subsequently, numerous palynostratigraphical studies in the North Atlantic have established a range from the Late Jurassic to Early Cenomanian (Habib, 1972; 1978;
Williams & Bujak, 1980; Habib & Drugg, 1983; 1987; Riley & Fenton, 1984).
In Europe the species was recorded from the Early and Late Kimmeridgian, the Barremian and Aptian -Albian of England (Riding & Thomas, 1988; Duxbury, 1980; 1983), from the Ryazanian to ?early Valanginian of Denmark (Heilmann-Clausen, 1987), from the Late Kimmeridgian of southwestern France (loannides et aL, 1988) and from the Valanginian - Earl; Hsuterivian of the stratotype and parastratotype sections of southeastern France and Switzerland (Habib & Drugg, 1983; Monteil, 1992, 1993).
In Africa, W. cylindricum has been documented from the Early Valanginian of southwestern Morocco (Below, 1982). In a study of the Berriasian to Barremian of the Speeton Clay in eastern England (Monteil, unpublished) the species has been observed from the earliest Late Valanginian (unit D4c) to the late Hauterivian (unit C2c).
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Emended Diagnosis. Riding 1994, p. 18-19
Proximate, epicavate, small dinoflagellate cysts with an elongate, subcylindrical ambitus. Pericyst has straight, slightly convex or concave lateral sides and rounded antapex and apex; endocyst subspherical, positioned at antapex. Periphragm smooth, relatively thin; endophragm smooth, relatively thick. Both cyst layers in loose mutual contact. Periarcheopyle apical, type (tA); perioperculum hemispherical, free. Endoarcheopyle apical, type (tA); endoperculum hemispherical, free or attached. Paratabulation normally expressed by peri-archeopyle only; Kofoidian formula apparently ?pr, 4', 6", as. Paracingulum rarely indicated by equatorial constriction of periphragm; parasulcus not reflected.
Description. Riding 1994, p. 18-19
A small, psilate, epicavate, longitudinally elongate species of Wallodinium. The pericyst is cylindrical, with straight, slightly convex to markedly concave lateral sides. The subspherical endocyst is antapically positioned and occasionally may be lost as a consequence of the loose adhesion between the cyst layers. The perioperculum comprises the apical paraplates and is rarely attached ventrally. The endoperculum is also apical, type (tA) and may be attached. An apparently gonyaulacacean epicystal paratabulation is expressed by the principal periarcheopyle suture only. A paracingulum may be expressed by a faint equatorial concavity of the periphragm
situated immediately anterior of the endocyst.
Dimensions (µm). 37 specimens measured.
Minimum Mean Maximum
Pericyst length 38.7 45.6 60.2
Pericyst width 25.1 34.2 43.3
Endocyst length 19.9 29.4 38.4
Endocyst width 26.4 32.5 42.7
Habib (1970, p.374) reported that the overall dimensions of the type material are 27 µm by 36 µm. The measured specimens from Europe are significantly larger; the equivalent average dimensions being 34 µm by 46 µm (see above).
Remarks: Riding 1994, p. 18-19
Wallodinium cylindricum is superficially similar to the Lower Jurassic morphotype Wallodinium sp. A.
Both forms are epicavate and the pericysts are typically equatorially constricted. The species differ, however, in that Wallodinium cylindricum has a free, hemispherical perioperculum, the suture of which apparently indicates a gonyaulacacean paratabulation. The perioperculum of Wallodinium sp. A, by contrast, is attached, virtually flat and has faint angulations at the margin (Prauss,1989, text-fig. 23). The endoarcheopyle of Wallodinium cylindricum is apical, with a free or attached endoperculum (Plate l, figs. 16, 18-20); in Wallodinium sp. A it is consistently adnate (type tAa). Wallodinium cylindricum has an endocyst which is loosly attached to the periphragm and is smaller in comparison with the capsule of Wallodinium sp. A. The cyst layers of Wallodinium sp. A are closely appressed. The equatorial constriction, where present, in Wallodinium cylindricum is distinctly anterior to the endocyst. In Wallodinium sp. A, there is a consistent concavity at the posterior margin of the paracingulum, where the cyst layers separate (Prauss, 1989, text-fig 23).
The remaining six species of Wallodinium (see Lentin and Williams, 1993, p. 669) are all more longitudinally elongate than W. cylindricum. Wallodinium anglicum (Cookson & Hughes 1964) Lentin & Williams 1973, W. bidigitatum (Manum & Cookson 1964) Lentin & Williams 1973 and W. Iuna (Cookson & Eisenack 1960) Lentin & Williams 1973 are crescent shaped and circumcavate. The endocyst of Wallodinium bidigitatum has two horns. Wallodinium glaessneri (Cookson & Eisenack 1960) LoeblichJr. & Loeblich III 1968, W. inflatum (Habib 1969) Habib 1970 and W. krutzschii (Alberti 1961) Habib 1972 are most similar to W. cylindricum, but are all bicavate. The loosly appressed periphragm and endophragm of Wallodinium cylindricum are unusual in that, typically, cavate gonyaulacacean forms have tightly appressed wall layers (Eaton, 1984). Wallodinium cylindricum may also resemble Phallocysta elongata (Beju 1971) comb. nov., emend. nov. The latter differs in having an anterior intercalary, type 31, peri- archeopyle and a characteristically elongate triangular ambitus.
Stratigraphic and Geographic Distribution: Wallodinium cylindricum has been reported from the uppermost Jurassic to Cretaceous (Ryazanian to lowermost Cenomanian) of the North Atlantic and Gulf of Mexico region (Habib,1970; 1972; 1977; 1978; Williams & Bujak, 1980; Riley & Fenton,1984; Habib & Drugg,1983; 1987). In north-west Europe, the range of this species has been determined as Upper Jurassic (Kimmeridgian) to Lower Cretaceous (Ryazanian to lower Albian) (Text-Figure 2). In England, Wallodinium cylindricum was recorded from the Kimmeridgian of Dorset (Riding and Thomas, 1988), the Barremian and Valanginian to Hauterivian of eastern England (Duxbury, 1980 and personal observations respectively) and the Aptian to lower Albian of southern England (Duxbury,1983). The species is also present in the upper Kimmeridgian and Valanginian to lower Hauterivian of southern France (Ioannides et al., 1988 and Habib and Drugg, 1983 respectively) and the Ryazanian to lower Valanginian of Denmark (Heilmann-Clausen, 1987). Below (1982) recorded Wallodinium cylindricum from the Moroccan Lower Cretaceous (Valanginian).
Synonyms:
Prismatocystis cylindrica Habib,1970, p.374, pl.10, fig.2; Riley & Fenton,1984, pl.4, fig.6; Habib & Drugg,1987, pl. 1,fig.6.
Hexagonifera cylindrica (Habib,1970, p.374, pl.10, fig.2) Habib 1972, p. 378, pl. 10. fig. 5.
Wallodinium elongatum auct. non (Beju,1971, p.289,290, pl.3, figs.7- 10, text-fig.6) Duxbury,1980, p.136, pl.11, fig. 11.
Wallodinium krutzschi auct. non (Alberti,1961, p.21, pl .7, figs. 19-21, pl. 12, figs. 6-7) Habib 1972, p. 378; Williams & Bujak, 1980, pl. 2, fig. 5.
Fromea elongata auct. non Beju, 1971, p. 289, 290, pl. 3, figs. 7-10, text-fig. 6; Below, 1982, pl. 4, fig. 12.
Wallodinium cylindricum (Habib, 1970, p.374, pl.10, fig. 2) Duxbury, 1983, p. 68, pl. 9, fig. 16; Heilmann-Clausen, 1987, pl.5, figs. 19-21; Ioannides et al., 1988, pl. 2, figs. 11, 12.
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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.
Wallodinium cylindricum (Habib, 1970) Duxbury, 1983, emend. Prauss, 1989, emend. Riding, 1994, emend. Feist-Burkhardt and Monteil, 1994. Emendation from Feist-Burkhardt and Monteil (1994), dinoflagellate cyst. Proximate, epicavate, with straight longitudinal axis. Pericyst stocky, subcylindrical with a broadly rounded antapex. Endocyst subspherical, relatively free in the pericyst, and consistently located at antapex when present. Peri- and endophragm psilate. Periarcheopyle apical type (tA). Endoarcheopyle type undetermined. Perioperculum dome shaped, generally free. Endoperculum attached. Paratabulation formula 4', 6", + as. Paracingulum may be indicated by a weak constriction situated at about half the cyst length, above top of endocyst. Parasulcus not indicated except as. Size: pericyst length 40-43 µm, width 26-29 µm, endocyst length 25-26 µm, width 24-29 µm. This species differs from Prismatocystis ewingii in having a broadly rounded antapex rather than a pyramidal antapex. Wallodinium krutzschii is bicavate to circumcavate, elongate fusiform with a narrowly rounded to pointed antapex.
According to Riding (1994) this is a small, proximate, epicavate, cyst with an elongate, subcylindrical ambitus. Pericyst has straight, slightly convex or concave lateral sides and rounded antapex, and apex; endocyst subspherical, positioned at antapex. Periphragm smooth, relatively thin; endophragm smooth, relatively thick. Both cyst layers in loose mutual contact. Periarcheopyle apical, type (tA); perioperculum hemispherical, free. Endoarcheopyle apical, type (tA), free or attached. Paratabulation normally expressed by periarcheopyle only; Kofoidian formula apparently ?pr, 4', 6", as. Paracingulum rarely indicated by equatorial constriction of periphragm; parasulcus not reflected. Habib (1970) gave the overall dimensions of the type material as 27 by 36 µm. The European specimens are significantly larger being 34 by 46 µm.
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Wallodinium cylindricum (Habib, 1970) Duxbury, 1983; Emendations: Prauss, 1989, p.47–48; Riding, 1994, p.18; Feist-Burkhardt and Monteil, 1994, p.7, all as Wallodinium cylindricum.
Originally Prismatocystis, subsequently Hexagonifera, thirdly (and now) Wallodinium.
Taxonomic junior synonym: Fromea (as Wallodinium, now Phallocysta) elongata, according to Duxbury (1983, p.68) — however, Feist-Burkhardt and Monteil in Feist-Burkhardt (1990, p.615) retained Fromea (as Andreedinium) elongata.
Holotype: Habib, 1970, pl.10, fig.2
Locus typicus: Core RC10-282, near the Horizon Beta deep-sea outcrop, Atlantic
Stratum typicum: Middle Cretaceous
Age: Albian-Cenomanian
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Original description Habib 1970, p. 374: Prismatocystis cylindrica
Prismatic acritarch, with a broadly rounded to subpyramidal closed apex opposite an open truncated apex. Periphragm sides straight or slightly convex.. Endophragm circular in outline, frequently open and folded, its diameter approximately half the length of the periphragm, located near closed apex, thinner (less than one micron in thickness) than periphragm. Periphragm and endophragm psilate.
Remarks: P. cylindrica is distinguished by its rounded apex and size, The endophragm is missing in two of the six specimens.
Occurence: Rare in all cores but RC10-284. Most common in core RC10-282.
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Emended description: Feist-Burkhardt & Monteil 1994, p. 7
Dinoflagellate cyst. Proximate, epicavate, with straight longitudinal axis. Pericyst stocky, subcylindrical with a broadly rounded antapex. Endocyst subspherical, relatively free in the pericyst, and consistently located at antapex when present. Peri- and endophragm psilate. Periarchaeopyle apical, type (tA). Endoarchaeopyle type undetermined. Perioperculum domeshaped, generally free. Endoperculum attached. Paratabulation generally expressed by archaeopyle only. Partial paratabulation formula: 4', 6" + as. Paracingulum may be indicated by a weak constriction situated at about half the cyst length, above top of endocyst. Parasulcus not indicated, except as.
Observed size range: Length of pericyst: 40-43 µm ; width of pericyst: 26-29 µm; length of endocyst: 25-26 µm; width of endocyst: 24-29 µm.
Comparisons: Wallodinium cylindricum n. emend. differs from Prismatocystis ewingii Habib 1969 in having a broadly rounded antapex rather than a pyramidal antapex. W krutzschii (Alberti 1961) Habib 1972 is bicavate to circumcavate, elongate fusiform, with a narrowly rounded to pointed antapex.
Previously reported occurrences: Feist-Burkhardt & Monteil 1994, p. 7
Wallodinium cylindricum was first described from Albian to Cenomanian deep-sea sediments from northeast of the Bahamas. Subsequently, numerous palynostratigraphical studies in the North Atlantic have established a range from the Late Jurassic to Early Cenomanian (Habib, 1972; 1978;
Williams & Bujak, 1980; Habib & Drugg, 1983; 1987; Riley & Fenton, 1984).
In Europe the species was recorded from the Early and Late Kimmeridgian, the Barremian and Aptian -Albian of England (Riding & Thomas, 1988; Duxbury, 1980; 1983), from the Ryazanian to ?early Valanginian of Denmark (Heilmann-Clausen, 1987), from the Late Kimmeridgian of southwestern France (loannides et aL, 1988) and from the Valanginian - Earl; Hsuterivian of the stratotype and parastratotype sections of southeastern France and Switzerland (Habib & Drugg, 1983; Monteil, 1992, 1993).
In Africa, W. cylindricum has been documented from the Early Valanginian of southwestern Morocco (Below, 1982). In a study of the Berriasian to Barremian of the Speeton Clay in eastern England (Monteil, unpublished) the species has been observed from the earliest Late Valanginian (unit D4c) to the late Hauterivian (unit C2c).
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Emended Diagnosis. Riding 1994, p. 18-19
Proximate, epicavate, small dinoflagellate cysts with an elongate, subcylindrical ambitus. Pericyst has straight, slightly convex or concave lateral sides and rounded antapex and apex; endocyst subspherical, positioned at antapex. Periphragm smooth, relatively thin; endophragm smooth, relatively thick. Both cyst layers in loose mutual contact. Periarcheopyle apical, type (tA); perioperculum hemispherical, free. Endoarcheopyle apical, type (tA); endoperculum hemispherical, free or attached. Paratabulation normally expressed by peri-archeopyle only; Kofoidian formula apparently ?pr, 4', 6", as. Paracingulum rarely indicated by equatorial constriction of periphragm; parasulcus not reflected.
Description. Riding 1994, p. 18-19
A small, psilate, epicavate, longitudinally elongate species of Wallodinium. The pericyst is cylindrical, with straight, slightly convex to markedly concave lateral sides. The subspherical endocyst is antapically positioned and occasionally may be lost as a consequence of the loose adhesion between the cyst layers. The perioperculum comprises the apical paraplates and is rarely attached ventrally. The endoperculum is also apical, type (tA) and may be attached. An apparently gonyaulacacean epicystal paratabulation is expressed by the principal periarcheopyle suture only. A paracingulum may be expressed by a faint equatorial concavity of the periphragm
situated immediately anterior of the endocyst.
Dimensions (µm). 37 specimens measured.
Minimum Mean Maximum
Pericyst length 38.7 45.6 60.2
Pericyst width 25.1 34.2 43.3
Endocyst length 19.9 29.4 38.4
Endocyst width 26.4 32.5 42.7
Habib (1970, p.374) reported that the overall dimensions of the type material are 27 µm by 36 µm. The measured specimens from Europe are significantly larger; the equivalent average dimensions being 34 µm by 46 µm (see above).
Remarks: Riding 1994, p. 18-19
Wallodinium cylindricum is superficially similar to the Lower Jurassic morphotype Wallodinium sp. A.
Both forms are epicavate and the pericysts are typically equatorially constricted. The species differ, however, in that Wallodinium cylindricum has a free, hemispherical perioperculum, the suture of which apparently indicates a gonyaulacacean paratabulation. The perioperculum of Wallodinium sp. A, by contrast, is attached, virtually flat and has faint angulations at the margin (Prauss,1989, text-fig. 23). The endoarcheopyle of Wallodinium cylindricum is apical, with a free or attached endoperculum (Plate l, figs. 16, 18-20); in Wallodinium sp. A it is consistently adnate (type tAa). Wallodinium cylindricum has an endocyst which is loosly attached to the periphragm and is smaller in comparison with the capsule of Wallodinium sp. A. The cyst layers of Wallodinium sp. A are closely appressed. The equatorial constriction, where present, in Wallodinium cylindricum is distinctly anterior to the endocyst. In Wallodinium sp. A, there is a consistent concavity at the posterior margin of the paracingulum, where the cyst layers separate (Prauss, 1989, text-fig 23).
The remaining six species of Wallodinium (see Lentin and Williams, 1993, p. 669) are all more longitudinally elongate than W. cylindricum. Wallodinium anglicum (Cookson & Hughes 1964) Lentin & Williams 1973, W. bidigitatum (Manum & Cookson 1964) Lentin & Williams 1973 and W. Iuna (Cookson & Eisenack 1960) Lentin & Williams 1973 are crescent shaped and circumcavate. The endocyst of Wallodinium bidigitatum has two horns. Wallodinium glaessneri (Cookson & Eisenack 1960) LoeblichJr. & Loeblich III 1968, W. inflatum (Habib 1969) Habib 1970 and W. krutzschii (Alberti 1961) Habib 1972 are most similar to W. cylindricum, but are all bicavate. The loosly appressed periphragm and endophragm of Wallodinium cylindricum are unusual in that, typically, cavate gonyaulacacean forms have tightly appressed wall layers (Eaton, 1984). Wallodinium cylindricum may also resemble Phallocysta elongata (Beju 1971) comb. nov., emend. nov. The latter differs in having an anterior intercalary, type 31, peri- archeopyle and a characteristically elongate triangular ambitus.
Stratigraphic and Geographic Distribution: Wallodinium cylindricum has been reported from the uppermost Jurassic to Cretaceous (Ryazanian to lowermost Cenomanian) of the North Atlantic and Gulf of Mexico region (Habib,1970; 1972; 1977; 1978; Williams & Bujak, 1980; Riley & Fenton,1984; Habib & Drugg,1983; 1987). In north-west Europe, the range of this species has been determined as Upper Jurassic (Kimmeridgian) to Lower Cretaceous (Ryazanian to lower Albian) (Text-Figure 2). In England, Wallodinium cylindricum was recorded from the Kimmeridgian of Dorset (Riding and Thomas, 1988), the Barremian and Valanginian to Hauterivian of eastern England (Duxbury, 1980 and personal observations respectively) and the Aptian to lower Albian of southern England (Duxbury,1983). The species is also present in the upper Kimmeridgian and Valanginian to lower Hauterivian of southern France (Ioannides et al., 1988 and Habib and Drugg, 1983 respectively) and the Ryazanian to lower Valanginian of Denmark (Heilmann-Clausen, 1987). Below (1982) recorded Wallodinium cylindricum from the Moroccan Lower Cretaceous (Valanginian).
Synonyms:
Prismatocystis cylindrica Habib,1970, p.374, pl.10, fig.2; Riley & Fenton,1984, pl.4, fig.6; Habib & Drugg,1987, pl. 1,fig.6.
Hexagonifera cylindrica (Habib,1970, p.374, pl.10, fig.2) Habib 1972, p. 378, pl. 10. fig. 5.
Wallodinium elongatum auct. non (Beju,1971, p.289,290, pl.3, figs.7- 10, text-fig.6) Duxbury,1980, p.136, pl.11, fig. 11.
Wallodinium krutzschi auct. non (Alberti,1961, p.21, pl .7, figs. 19-21, pl. 12, figs. 6-7) Habib 1972, p. 378; Williams & Bujak, 1980, pl. 2, fig. 5.
Fromea elongata auct. non Beju, 1971, p. 289, 290, pl. 3, figs. 7-10, text-fig. 6; Below, 1982, pl. 4, fig. 12.
Wallodinium cylindricum (Habib, 1970, p.374, pl.10, fig. 2) Duxbury, 1983, p. 68, pl. 9, fig. 16; Heilmann-Clausen, 1987, pl.5, figs. 19-21; Ioannides et al., 1988, pl. 2, figs. 11, 12.
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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.
Wallodinium cylindricum (Habib, 1970) Duxbury, 1983, emend. Prauss, 1989, emend. Riding, 1994, emend. Feist-Burkhardt and Monteil, 1994. Emendation from Feist-Burkhardt and Monteil (1994), dinoflagellate cyst. Proximate, epicavate, with straight longitudinal axis. Pericyst stocky, subcylindrical with a broadly rounded antapex. Endocyst subspherical, relatively free in the pericyst, and consistently located at antapex when present. Peri- and endophragm psilate. Periarcheopyle apical type (tA). Endoarcheopyle type undetermined. Perioperculum dome shaped, generally free. Endoperculum attached. Paratabulation formula 4', 6", + as. Paracingulum may be indicated by a weak constriction situated at about half the cyst length, above top of endocyst. Parasulcus not indicated except as. Size: pericyst length 40-43 µm, width 26-29 µm, endocyst length 25-26 µm, width 24-29 µm. This species differs from Prismatocystis ewingii in having a broadly rounded antapex rather than a pyramidal antapex. Wallodinium krutzschii is bicavate to circumcavate, elongate fusiform with a narrowly rounded to pointed antapex.
According to Riding (1994) this is a small, proximate, epicavate, cyst with an elongate, subcylindrical ambitus. Pericyst has straight, slightly convex or concave lateral sides and rounded antapex, and apex; endocyst subspherical, positioned at antapex. Periphragm smooth, relatively thin; endophragm smooth, relatively thick. Both cyst layers in loose mutual contact. Periarcheopyle apical, type (tA); perioperculum hemispherical, free. Endoarcheopyle apical, type (tA), free or attached. Paratabulation normally expressed by periarcheopyle only; Kofoidian formula apparently ?pr, 4', 6", as. Paracingulum rarely indicated by equatorial constriction of periphragm; parasulcus not reflected. Habib (1970) gave the overall dimensions of the type material as 27 by 36 µm. The European specimens are significantly larger being 34 by 46 µm.
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