radiolaria - rads_cenozoic - Spirocyrtis gyroscalaris radiolaria - rads_cenozoic - Spirocyrtis gyroscalaris

Spirocyrtis gyroscalaris

Classification: rads_cenozoic -> Artostrobiidae -> Spirocyrtis -> Spirocyrtis gyroscalaris
Sister taxa: S. greeni, S. gyroscalaris, S. scalaris, S. subscalaris, S. subtilis, S. sp.


Citation: Spirocyrtis gyroscalaris Nigrini 1977
taxonomic rank: species
Basionym: Spirocyrtis gyroscalaris
1966 Siphocampium cf. cornutella - Benson pl. 35, figs. 16-17 (not figs. 14-15)
1971 Spirocyrtis sp. aff. S. scalaris - Riedel and Sanfilippo pl. 1G, figs. 21, 23 (not Figs. 19,20,22,24)
1977 Spirocyrtis gyroscalaris - Nigrini pl. 2, figs. 10, 11
Taxonomic discussion: Nigrini 1977; Alexandrovich 1989 (ODP 111 SR) pl.3 fig.13

Catalog entries: Spirocyrtis gyroscalaris

Original description: Similar in form to S. scalaris, but the outline of the segments is rounded rather than angular; it is generally narrower than S. scalaris, becoming broader in younger sediments as it evolves into S. scalaris. Duck-billed vertical tube and three-bladed apical horn both well developed. Seven to nine segments of variable length with two to five rows of subcircular to rectangular pores per segment. Termination ragged.

(based on 70 specimens). Total length 130-180µm; maximum breadth 75-105µm.

Phylogeny: Ancestor of S. scalaris and descendant of S. subtilis.


Biogeography and Palaeobiology

Biostratigraphic distribution

Geological Range:
Last occurrence (top): within Neogene Period (2.59-23.03Ma, top in Piacenzian stage). Data source: Lazarus et al. 2015 - "N age group"
First occurrence (base): within Neogene Period (2.59-23.03Ma, base in Aquitanian stage). Data source: Lazarus et al. 2015 - "N age group"

Plot of occurrence data:


Alexandrovich, J. M. (1989). Radiolarian biostratigraphy of ODP Leg 111, Site 677, eastern equatorial Pacific, late Miocene through Pleistocene. Proceedings of the Ocean Drilling Program, Scientific Results. 111: 245-262. gs

Benson, R. N. (1966). Recent Radiolaria from the Gulf of California. Thesis, Minnesota University. 1-577. gs

Nigrini, C. A. (1977). Tropical Cenozoic Artostrobiidae (Radiolaria). Micropaleontology. 23(3): 241-269. gs

Riedel, W. R. & Sanfilippo, A. (1971). Cenozoic Radiolaria from the western tropical Pacific, Leg 7. Initial Reports of the Deep Sea Drilling Project. 7: 1529-1666. gs


Spirocyrtis gyroscalaris compiled by the radiolaria@mikrotax project team viewed: 17-6-2024

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