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Horologinella coninckii
From Fensome et al., 2019:
Horologinella coninckii Slimani, 1994, p.103, pl.14, figs.12–15. Holotype: Slimani, 1994, pl.14, figs.12–13. Age: latest Maastrichtian–Danian.
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Original description (translation PKB 2025)
Type species:
Horologinella lineala COOKSON and EISENACK, 1962a
Derivation of the name: In honor of Dr. Jan DECONINCK, Universiteit Gent, Geologisch Instituut, Laboratorium voor Paléontologie, Belgium.
Holotvpe: Turnhout -739.31 m, preparation 8, eoord. E.F. L27.
Type locality: Turnhout -739.31 m.
Horizon type: Danien
Diagnosis:
Small, non-tabulated Horologinella cyst, often dorsoventrally flattened and resembling a hyperboloid with long wedges with slightly bulbous bases and mammillary apexes. The apical and antapical surfaces are straight or very slightly concave or convex; the two lateral surfaces are strongly concave and often with a marked equatorial constriction. The hourglass-shaped endocyst is always present. A very thin and fragile ectophragm completely or partially covers the cyst.
Dimensions:
Holotype: pericyst, length: 23 µm, width: 30 µm; endocyst, length: 20 µm, width: µm.
Variations: pericyst, length: 20-30 µm, width: 20-30 µm; Endocyst, length: 11 - 18 µm, width: 8 -14 µm. Number of specimens measured: 10. Material: 20 specimens.
Description:
The thin, smooth, hyaline endophragm and periphragm are almost always separate but closer together at the equatorial constrictions. The endocyst is longitudinally elongated. The hyaline, finely stippled ectophragm is very rarely detached. This species has neither an archaeopyle nor evidence of paratabulation: it is probably among other species of this genus that STOVER and EVITT (1978: p. 54) considered acritarchs.
Comparison:
H. angulata DE CONINCK (1985), from the Middle Eocene of Belgium, is the species that most closely resembles H. coninckii sp. Nov., but the latter is distinguished by its more clearly pronounced corners, its more strongly concave lateral faces, and the presence of a small pericoel separating the endophragm and periphragm, as well as the presence of an ectophragm that completely or partially covers the cyst.
Stratigraphic distribution:
Turnhout: -807.90 to -739.31 m. Upper part of the Upper Maastrichtian - Danian.
Horologinella coninckii Slimani, 1994, p.103, pl.14, figs.12–15. Holotype: Slimani, 1994, pl.14, figs.12–13. Age: latest Maastrichtian–Danian.
---------------------------------------------------------------------------------------------------
Original description (translation PKB 2025)
Type species:
Horologinella lineala COOKSON and EISENACK, 1962a
Derivation of the name: In honor of Dr. Jan DECONINCK, Universiteit Gent, Geologisch Instituut, Laboratorium voor Paléontologie, Belgium.
Holotvpe: Turnhout -739.31 m, preparation 8, eoord. E.F. L27.
Type locality: Turnhout -739.31 m.
Horizon type: Danien
Diagnosis:
Small, non-tabulated Horologinella cyst, often dorsoventrally flattened and resembling a hyperboloid with long wedges with slightly bulbous bases and mammillary apexes. The apical and antapical surfaces are straight or very slightly concave or convex; the two lateral surfaces are strongly concave and often with a marked equatorial constriction. The hourglass-shaped endocyst is always present. A very thin and fragile ectophragm completely or partially covers the cyst.
Dimensions:
Holotype: pericyst, length: 23 µm, width: 30 µm; endocyst, length: 20 µm, width: µm.
Variations: pericyst, length: 20-30 µm, width: 20-30 µm; Endocyst, length: 11 - 18 µm, width: 8 -14 µm. Number of specimens measured: 10. Material: 20 specimens.
Description:
The thin, smooth, hyaline endophragm and periphragm are almost always separate but closer together at the equatorial constrictions. The endocyst is longitudinally elongated. The hyaline, finely stippled ectophragm is very rarely detached. This species has neither an archaeopyle nor evidence of paratabulation: it is probably among other species of this genus that STOVER and EVITT (1978: p. 54) considered acritarchs.
Comparison:
H. angulata DE CONINCK (1985), from the Middle Eocene of Belgium, is the species that most closely resembles H. coninckii sp. Nov., but the latter is distinguished by its more clearly pronounced corners, its more strongly concave lateral faces, and the presence of a small pericoel separating the endophragm and periphragm, as well as the presence of an ectophragm that completely or partially covers the cyst.
Stratigraphic distribution:
Turnhout: -807.90 to -739.31 m. Upper part of the Upper Maastrichtian - Danian.