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Pyxidinopsis everriculum
Pyxidinopsis everriculum Willumsen, 2011, p.228,230, figs.13C–F.
Holotype: Willumsen, 2011, fig.13F. N.I.A.
Age: late Maastrichtian–earliest Paleocene.
Original description (Willumsen, 2011)
Types. Holotype, Mead Stream, P30/f906, slide L18315/3, 6 μm, EF: L39,4; M39,2 (Fig. 13F). Paratype, Mead Stream, same sample & slide as holotype, EF: Q48,2 (Fig. 13D.Type unit and locality. Mead Hill Formation, Mead Stream section, Clarence Valley, Marlborough.
Etymology. Everriculum (Latin)=dragnet, with reference to the finely reticulate surface ornamentation of this dinoflagellate cyst.
Diagnosis. Subspherical Pyxidinopsis with a regular, low reticulum consisting of relatively small lumina of ca 1–2 μm wide. Paratabulation indicated only by archeopyle type P(3″).
Description. Small subspherical gonyaulacoid dinocyst with a regular reticulate surface ornamentation. Reticulum consists of ca 1 μm high muri and ca 1–2 μm wide lumina (Fig. 13E). Thickness of the autophragm is 1–2 μm. Paratabulation is indicated only by a precingular archeopyle formed by the loss of paraplate 3″. Operculum is quader form, type P (3″) and it is commonly attached to the archeopyle margin along the contact between cingular plates or paraplate 2″ or 4″. Diameter 38(44)48 μm [8 specimens measured].
Remarks. Pyxidinopsis everriculum differs from P. meadensis by being smaller and having a regular low reticulum; it is about the same size as P. epakros, but has a regular reticulum without spines; and is slightly larger than P. ardonensis Jan du Chêne, 1988. Pyxidinopsis sp. A of Crouch, 2001 Crouch, E. M. 2001. Environmental Change at the Time of the Paleocene–Eocene Biotic Turnover, 216Balkema: Utrecht University. LPP Contribution Series 14
(p. 60, fig. 8) resembles P. everriculum, but is smaller (ca 30 × 32 μm). Pyxidinopsis waipawaensis is larger than P. everriculum and has an irregular reticulate surface ornamentation with a thicker autophragm.
Age and distribution. The FO of Pyxidinopsis everriculum sp. nov. is below the sampled interval of this study, but the LO is in the earliest Paleocene correlated to radiolarian zone RP2. Pyxidinopsis everriculum is common to abundant in sections from the Marlborough area. It was recorded from Branch Stream, Fairfield Quarry, Mead Stream, mid-Waipara River, Wharanui Point and Woodside Creek.
Holotype: Willumsen, 2011, fig.13F. N.I.A.
Age: late Maastrichtian–earliest Paleocene.
Original description (Willumsen, 2011)
Types. Holotype, Mead Stream, P30/f906, slide L18315/3, 6 μm, EF: L39,4; M39,2 (Fig. 13F). Paratype, Mead Stream, same sample & slide as holotype, EF: Q48,2 (Fig. 13D.Type unit and locality. Mead Hill Formation, Mead Stream section, Clarence Valley, Marlborough.
Etymology. Everriculum (Latin)=dragnet, with reference to the finely reticulate surface ornamentation of this dinoflagellate cyst.
Diagnosis. Subspherical Pyxidinopsis with a regular, low reticulum consisting of relatively small lumina of ca 1–2 μm wide. Paratabulation indicated only by archeopyle type P(3″).
Description. Small subspherical gonyaulacoid dinocyst with a regular reticulate surface ornamentation. Reticulum consists of ca 1 μm high muri and ca 1–2 μm wide lumina (Fig. 13E). Thickness of the autophragm is 1–2 μm. Paratabulation is indicated only by a precingular archeopyle formed by the loss of paraplate 3″. Operculum is quader form, type P (3″) and it is commonly attached to the archeopyle margin along the contact between cingular plates or paraplate 2″ or 4″. Diameter 38(44)48 μm [8 specimens measured].
Remarks. Pyxidinopsis everriculum differs from P. meadensis by being smaller and having a regular low reticulum; it is about the same size as P. epakros, but has a regular reticulum without spines; and is slightly larger than P. ardonensis Jan du Chêne, 1988. Pyxidinopsis sp. A of Crouch, 2001 Crouch, E. M. 2001. Environmental Change at the Time of the Paleocene–Eocene Biotic Turnover, 216Balkema: Utrecht University. LPP Contribution Series 14
(p. 60, fig. 8) resembles P. everriculum, but is smaller (ca 30 × 32 μm). Pyxidinopsis waipawaensis is larger than P. everriculum and has an irregular reticulate surface ornamentation with a thicker autophragm.
Age and distribution. The FO of Pyxidinopsis everriculum sp. nov. is below the sampled interval of this study, but the LO is in the earliest Paleocene correlated to radiolarian zone RP2. Pyxidinopsis everriculum is common to abundant in sections from the Marlborough area. It was recorded from Branch Stream, Fairfield Quarry, Mead Stream, mid-Waipara River, Wharanui Point and Woodside Creek.