CATALOG OF ORIGINAL DESCRIPTIONS: Spirocyrtis gyroscalaris Nigrini 1977
This page provides data from the catalog of type descriptions. The catalog is sorted alphabetically. Use the current identification link to go back to the main database.
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 (rw): Ancestor of S. scalaris and descendant of S. subtilis.
References:
Nigrini, C. A. (1977). Tropical Cenozoic Artostrobiidae (Radiolaria). Micropaleontology. 23(3): 241-269. gs
Spirocyrtis gyroscalaris compiled by the radiolaria@mikrotax project teamviewed: 1-6-2023
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