radiolaria - rads_cat - Clathrocyclas universa undella

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Clathrocyclas universa undella

Citation: Clathrocyclas universa undella Clark & Campbell 1942

Type specimens: pl.7, figs.8-10,21,25

Type repository: University of California, Museum of Paleontology, San Francisco

Family (traditional): Theoperidae

Shell with strongly convex bell-shaped thorax and with stout, apical horn; apical horn sometimes but rarely (?) as much as 0.45 total length (Fig. 21), stout conical in side view (5°), with four, equal, opposite, apically decurrent, strongly twisted, thick, heavy blades which may extend the whole or nearly the whole length of the horn itself, the tip blunted, the base simple, mostly vertical, rarely bent to one side; cephalis rather narrowly conical (approximately 50°), its base about as wide as the altitude, coarsely convex, sometimes a little asymmetrical, the sides falling away rapidly, and basally limited by sharp change in contour; thorax the longest shell-segment (as much as 0.46 total length), very stout conical (about 52 in the upper part, thence 30°, later, in the lower 0.3 becoming contracted at 32° to the base), greatest diameter reached at or near the middle, the thorax limited basally by a narrow, internal, horizontal septal band; abdomen a short, sometimes flaring (45°) skirt although more often merely a short ring, its length almost never 0.1 total length; apertural margin regularly provided with a dozen (or more) equal, equidistant, subtriangular prongs or teeth, often irregular as if torn; wall and surface as in C. universa universa, n. subsp., save that the thoracic pores are a little smaller and within very shallow concave areas with less strong sepaloid points.

Length of Figure 8, 180µm; of horn, 50µm; of cephalis, 34.2µm; diameter of aperture, 87.0µm; of thoracic pores, 12.2µm.

Distinguishing characters: This subspecies differs from universa universa n.subsp. in more strongly convex thorax and different, bladed horn, in the former this part of the shell having two, opposite blades which are not so strongly twisted, and also the whole horn is stouter than in the other. There are fewer teeth around the aperture. The pores are less large and within shallower concave areas. It differs from the several varieties— universa longispina, universa amplaspina n.vars.—in either length or stoutness of apical horn, or else from universa cylindrica and universa grandis n.vars. in less strongly developed abdomen. Like universa universa n.subsp. it is very abundant.

[The authors here list this species under the subgeneric name Clathrocyclia and include the subgeneric name in the species name.

References:

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

CATALOG OF ORIGINAL DESCRIPTIONS: Clathrocyclas universa undella Clark & Campbell 1942

Clathrocyclas universa undella

References:

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