radiolaria - rads_cat - Zygospyris duplex radiolaria - rads_cat - Zygospyris duplex

CATALOG OF ORIGINAL DESCRIPTIONS: Zygospyris duplex Clark & Campbell 1942

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.

Higher levels: rads_cat -> Z -> Zygospyris -> Zygospyris duplex
Other pages this level: Z. brevispina, Z. demissa, Z. duplex, Z. equus, Z. quadrupes

Zygospyris duplex

Citation: Zygospyris duplex Clark & Campbell 1942
Rank: species
Described on page(s) : p.59
Type specimens: pl.9, fig.1
Type repository: University of California, Museum of Paleontology, San Francisco
Family (traditional): Trissocyclidae
Family (modern): Triospyridae

Current identification:

Original Description

Shell strongly dipleuric, nut-shaped, with an apical horn and feet; shell divided into two equal lobes by a sagittal stricture or notch, the lobes separated by a deep, narrow groove, lobes elevated slightly and also inflated; pores very large, gate like, four or five on one side of one lobe and one or two additional smaller ones toward the apertural end, mostly subrectangular, triangular, or subcircular (the smaller ones), generally arranged in two or three vertical and horizontal rows, very similar on both sides; the framework very strong, with rounded bars and beams, hyaline; coryphal surface with a single, sagittal, central, small, conical apical horn; feet four or five (?), all broken off near the bases in the photographed specimen, apparently two of them pectoral and two tergal, the sagittal or great-circle strongly prismatic, thick; aperture the simple opening of the shell with interradial, strongly arched beams of the shell framework forming its margin, the arches sometimes with short, outer serrated edge near the base of the foot.

Length of shell, 76.0µm; of apical horn, 10.0µm; breadth of shell, 80µm; of largest midsagittal pore, 25.4µm. Distinguishing characters (rw): Zygospyris duplex n. sp. differs from Z. equis Haeckel (1887) in shell shape and character of horn and feet. It is apparently much more like Z. quadripes Haeckel (1887), but the surface is not tuberculate.
The lack of the feet in the broken specimen is such that generic identification is not satisfactory.


Clark, B. L. & Campbell, A. S. (1942a). Eocene radiolarian faunas from the Mt. Diablo area, California. Geological Society of America, Special Papers. 39: 1-112. gs


Zygospyris duplex compiled by the radiolaria@mikrotax project team viewed: 2-4-2023

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