Back
Impagidinium bellunoensis
Original description Iakovleva 2025:
Impagidinium bellunoensis sp. nov.
Plate II, 1–3, 6–8, 11–16; Plate III, 4–9; Plate IV, 1–9.
Etymology: Named for the NE Italian province of Belluno, home to the Alano di Piave section, GSSP for the Bartonian/Priabonian boundary.
Type locality and horizon: Sample A5969, level 59,69 m, Alano di Piave section, Italy.
Holotype: Plate II, 1–3, 6–8; Sample A5969, slide 1, EF = Q20. University of Utrecht, The Netherlands.
Paratype: Plate II, 11–16; Sample A6357, slide 2, EF = J28–4.
Studied material: Alano di Piave section, Italy.
Stratigraphic horizon: Uppermost Bartonian - lower Priabonian. Future studies will further determine its entire stratigraphic range.
Diagnosis: A large sized species of Impagidinium, oval in outline, with microperforated slightly meandering parasutural septa of intermediate hight, with irregular distal terminations.
Description:
Shape: Ovoidal.
Wall relationships: A smooth endophragm is overlain by a closely appressed granulated to microreticulated periphragm giving rise to smooth parasutural septa of intermediate height.
Wall features: Endophragm smooth, overlain by a closely appressed thinner periphragm giving rise to slightly curved parasutural septa of intermediate height. Septa striated and distinctly microperforated, distally irregularly denticulate.
Processes: Absent.
Paratabulation: Indicated by parasutural features (septa); sexiform gonyaulacean; formula 4′, 5–6″, 5c, 5″’, 1p, 1″”.
Archeopyle: Precingular, type P (paraplate 3″), operculum free.
Dimensions: Holotype. 70 × 63 μm, septa 10–14 μm. Paratype. 72 × 66 μm, septa 11–14 μm. Total diameters central body range ∼ 67 × 85 μm (10 specimens), height of septa 8–15 μm.
Comparison: I. bellunoensis sp. nov. is somewhat similar to I. victorianum, but differs by having a microreticulate surface and distinctly more perforated septa. It also resembles Ynezidinium brevisulcatum, but differs by having 3 apical plates reflected rather than 4, being somewhat smaller in overall size, having more ‘meandering’ parasutural septa, which are more heavily perforated, and which terminate in a much more irregular denticulate fashion.
Impagidinium bellunoensis sp. nov.
Plate II, 1–3, 6–8, 11–16; Plate III, 4–9; Plate IV, 1–9.
Etymology: Named for the NE Italian province of Belluno, home to the Alano di Piave section, GSSP for the Bartonian/Priabonian boundary.
Type locality and horizon: Sample A5969, level 59,69 m, Alano di Piave section, Italy.
Holotype: Plate II, 1–3, 6–8; Sample A5969, slide 1, EF = Q20. University of Utrecht, The Netherlands.
Paratype: Plate II, 11–16; Sample A6357, slide 2, EF = J28–4.
Studied material: Alano di Piave section, Italy.
Stratigraphic horizon: Uppermost Bartonian - lower Priabonian. Future studies will further determine its entire stratigraphic range.
Diagnosis: A large sized species of Impagidinium, oval in outline, with microperforated slightly meandering parasutural septa of intermediate hight, with irregular distal terminations.
Description:
Shape: Ovoidal.
Wall relationships: A smooth endophragm is overlain by a closely appressed granulated to microreticulated periphragm giving rise to smooth parasutural septa of intermediate height.
Wall features: Endophragm smooth, overlain by a closely appressed thinner periphragm giving rise to slightly curved parasutural septa of intermediate height. Septa striated and distinctly microperforated, distally irregularly denticulate.
Processes: Absent.
Paratabulation: Indicated by parasutural features (septa); sexiform gonyaulacean; formula 4′, 5–6″, 5c, 5″’, 1p, 1″”.
Archeopyle: Precingular, type P (paraplate 3″), operculum free.
Dimensions: Holotype. 70 × 63 μm, septa 10–14 μm. Paratype. 72 × 66 μm, septa 11–14 μm. Total diameters central body range ∼ 67 × 85 μm (10 specimens), height of septa 8–15 μm.
Comparison: I. bellunoensis sp. nov. is somewhat similar to I. victorianum, but differs by having a microreticulate surface and distinctly more perforated septa. It also resembles Ynezidinium brevisulcatum, but differs by having 3 apical plates reflected rather than 4, being somewhat smaller in overall size, having more ‘meandering’ parasutural septa, which are more heavily perforated, and which terminate in a much more irregular denticulate fashion.