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Echinidinium nordlandense
Echinidinium nordlandense Head in Head et al., 2004, p.293–294, figs.3O–P,4A–L,7A–P.
Holotype: Head et al. 2004, figs.3O–P.
Age: Gelasian.
Original description (Head et al., 2004):
Echinidinium nordlandensis Head sp. nov. Figs. 3O and P, 4A–L and 7
Diagnosis. A species of Echinidinium with a smooth to scabrate central body surface bearing numerous processes of heterogenous morphology. Processes are hollow, with broad and narrow processes occurring on the same specimen. Likewise, process tips may be evexate, flared, bulbous, aculeate, acuminate or bifid, with or without secondary branching; one or two forms usually predominating on each specimen. Archeopyle theropylic, consisting of a short straight split. No other expression of tabulation.
Description. Spheroidal central body with thin wall (less than 0.3 µm) that shows no stratification under light microscopy except at process bases. Both central body and processes are light to medium brown. Processes are randomly distributed over the surface and distinguished by their heterogenous morphology (Fig. 7), with several forms occurring on each cyst although usually with one or two forms predominating, e.g. bifid and acuminate process tips on the holotype. Processes have a smooth surface and may be open or closed distally. The archeopyle is presumed to be theropylic, based on a short, straight split seen on occasional specimens.
Measurements.
Holotype: central body diameter 30 x 26 µm, maximum process length 6.5 µm.
Range (DSDP Hole 603C): maximum central body diameter 21 (24.3) 28 µm, maximum process length 3.5 (5.06) 7.0 µm. Eighteen specimens were measured.
Range (Nordland Group mudstone): maximum central body diameter 21 (26.5) 30 µm, maximum process length 4.0 (5.81) 7.0 µm. Thirteen specimens were measured.
Etymology. Named after the Nordland Group mudstones, which serve as the type stratum for this species.
Holotype. Fig. 3O and P. BGS specimen MPK 12797, slide 1, England Finder reference F35/4. Sample MPA 51092 at 906.00 m depth in Norwegian sector well 15/9- A-11. Curated at the British Geological Survey, Nottingham, UK.
Occurrence. Nordland Group mudstone, northern North Sea. Also restricted to the Gelasian (upper Upper Pliocene) of western North Atlantic DSDP Hole 603C, in four samples (core, section, interval) from the study of Head and Norris (2003): 8-5, 100–102 cm; 8-2, 100–102 cm; 7-2, 85– 87 cm; and 5-5, 100–102 cm.
Comparison. Echinidinium nordlandensis differs from all known species of the genus in the heterogenous morphology of its processes.
Holotype: Head et al. 2004, figs.3O–P.
Age: Gelasian.
Original description (Head et al., 2004):
Echinidinium nordlandensis Head sp. nov. Figs. 3O and P, 4A–L and 7
Diagnosis. A species of Echinidinium with a smooth to scabrate central body surface bearing numerous processes of heterogenous morphology. Processes are hollow, with broad and narrow processes occurring on the same specimen. Likewise, process tips may be evexate, flared, bulbous, aculeate, acuminate or bifid, with or without secondary branching; one or two forms usually predominating on each specimen. Archeopyle theropylic, consisting of a short straight split. No other expression of tabulation.
Description. Spheroidal central body with thin wall (less than 0.3 µm) that shows no stratification under light microscopy except at process bases. Both central body and processes are light to medium brown. Processes are randomly distributed over the surface and distinguished by their heterogenous morphology (Fig. 7), with several forms occurring on each cyst although usually with one or two forms predominating, e.g. bifid and acuminate process tips on the holotype. Processes have a smooth surface and may be open or closed distally. The archeopyle is presumed to be theropylic, based on a short, straight split seen on occasional specimens.
Measurements.
Holotype: central body diameter 30 x 26 µm, maximum process length 6.5 µm.
Range (DSDP Hole 603C): maximum central body diameter 21 (24.3) 28 µm, maximum process length 3.5 (5.06) 7.0 µm. Eighteen specimens were measured.
Range (Nordland Group mudstone): maximum central body diameter 21 (26.5) 30 µm, maximum process length 4.0 (5.81) 7.0 µm. Thirteen specimens were measured.
Etymology. Named after the Nordland Group mudstones, which serve as the type stratum for this species.
Holotype. Fig. 3O and P. BGS specimen MPK 12797, slide 1, England Finder reference F35/4. Sample MPA 51092 at 906.00 m depth in Norwegian sector well 15/9- A-11. Curated at the British Geological Survey, Nottingham, UK.
Occurrence. Nordland Group mudstone, northern North Sea. Also restricted to the Gelasian (upper Upper Pliocene) of western North Atlantic DSDP Hole 603C, in four samples (core, section, interval) from the study of Head and Norris (2003): 8-5, 100–102 cm; 8-2, 100–102 cm; 7-2, 85– 87 cm; and 5-5, 100–102 cm.
Comparison. Echinidinium nordlandensis differs from all known species of the genus in the heterogenous morphology of its processes.