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Pyxidinopsis ovis
Pyxidinopsis ovis Zevenboom and Santarelli in Zevenboom, 1995 manuscript name
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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.
Pyxidinopsis ovis Zevenboom and Santarelli in Zevenboom, 1995. Diagnosis from Zevenboom and Santarelli in Zevenboom (1995, p.153-154), A thick-walled elongate-ellipsoidal species of Pyxidinopsis with a microreticulate periphragm. This species differs from other species of Pyxidinopsis in having a very low surface ornamentation in its relatively thick wall. It differs from Tectatodinium pellitum in being elongate-ellipsoidal rather than spherical and in the periphragm not being composed of interconnected irregular perforate lamellae. Size: length 27-38 µm, width 20-25 µm, wall thickness 2-4 µm.
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Original description (Zevenboom, 1995)
Manuscript holotype: Sample Lem III 4/1, EF (F46), Plate IX, 1-3
Etmology: In reference to the oval shape of this species.
Type locality: Lemme Section, Tertiary Piedmont Basin, North Italy.
Type stratum: Rigoroso Formation
Diagnosis: A thick-walled elongate-ellipsoidal species of Pyxidinopsis with a microreticulate periphragm.
Dimension: Height: 27(33)38 µm; width: 20 (23)25 µm. Wall thickness: 2(3) 4 µm. N=20.
Description: An elongate-ellipsoidal species of Pyxidinopsis with a relatively thick periphragm. The endo- and periphragm are closely appressed. The periphragm is microreticulate. The archaeopyle is formed by the loss of paraplate 3", operculum free.
Discussion: Pyxidinopsis ovis differs from all other species of Pyxidinopsis in displaying only a very low surface ornamentation and in having a relatively thick wall. It differs from the morphologically similar Tectatodinium pellitum Wall, 1967, in being elongate-ellipsoidal, rather then spherical and the periphragm is not composed of interconnected, irregular perforate lamellae.
Occurences: Norwegian Sea (Manum et al., 1989), Baffin Bay (Head et al., 1989c), Italy (this study) and The Netherlands (this study.
Total stratigraphical range: Earliest Early Miocene to Late Miocene (this study).
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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.
Pyxidinopsis ovis Zevenboom and Santarelli in Zevenboom, 1995. Diagnosis from Zevenboom and Santarelli in Zevenboom (1995, p.153-154), A thick-walled elongate-ellipsoidal species of Pyxidinopsis with a microreticulate periphragm. This species differs from other species of Pyxidinopsis in having a very low surface ornamentation in its relatively thick wall. It differs from Tectatodinium pellitum in being elongate-ellipsoidal rather than spherical and in the periphragm not being composed of interconnected irregular perforate lamellae. Size: length 27-38 µm, width 20-25 µm, wall thickness 2-4 µm.
--------------------------------------------------
Original description (Zevenboom, 1995)
Manuscript holotype: Sample Lem III 4/1, EF (F46), Plate IX, 1-3
Etmology: In reference to the oval shape of this species.
Type locality: Lemme Section, Tertiary Piedmont Basin, North Italy.
Type stratum: Rigoroso Formation
Diagnosis: A thick-walled elongate-ellipsoidal species of Pyxidinopsis with a microreticulate periphragm.
Dimension: Height: 27(33)38 µm; width: 20 (23)25 µm. Wall thickness: 2(3) 4 µm. N=20.
Description: An elongate-ellipsoidal species of Pyxidinopsis with a relatively thick periphragm. The endo- and periphragm are closely appressed. The periphragm is microreticulate. The archaeopyle is formed by the loss of paraplate 3", operculum free.
Discussion: Pyxidinopsis ovis differs from all other species of Pyxidinopsis in displaying only a very low surface ornamentation and in having a relatively thick wall. It differs from the morphologically similar Tectatodinium pellitum Wall, 1967, in being elongate-ellipsoidal, rather then spherical and the periphragm is not composed of interconnected, irregular perforate lamellae.
Occurences: Norwegian Sea (Manum et al., 1989), Baffin Bay (Head et al., 1989c), Italy (this study) and The Netherlands (this study.
Total stratigraphical range: Earliest Early Miocene to Late Miocene (this study).