CATALOG OF ORIGINAL DESCRIPTIONS: Cyclampterium pegetrum Sanfilippo & Riedel 1970

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 -> C -> Cyclampterium -> Cyclampterium pegetrum
Other pages this level: C. brachythorax, C. leptetrum, C. longiventer, C. milowi, C. neatum, C. pegetrum, C. tanythorax

Cyclampterium pegetrum

Citation: Cyclampterium pegetrum Sanfilippo & Riedel 1970
Rank: species
Type specimens: pl.2, figs.8-10
Type repository: Holotype: CHUB 17, 11-15 cm.; USNM 167340, D33/3.
Described on page(s) : p.456
Family (traditional): Theoperidae
Family (modern): Lophocyrtiidae

<% linkedspecs %>

Current identification:

Original Description
Shell robust, campanulate to subcylindrical, with the abdomen usually constituting a half or more of the volume of the shell. Cephalis subspherical, poreless or with rather few small pores, in many specimens bearing a short, often thick, apical spine. Collar stricture pronounced. Thorax hemispherical. thick-walled, with sub-regular circular pores. and a surface which is smooth, thorny or nodose. Abdomen usually sub-cylindrical or slightly expanding distally, rarely inverted-hemispherical, with irregular robust meshwork much coarser than that of the thorax, in some specimens closed distally. Some specimens have three, or rarely more, irregular. subcylindrical feet which may be terminal or subterminal, and which arise, not at the lumbar stricture, but more distally.

(Based on 30 specimens) Total length 310-620µm, usually 340-470µm. Length of thorax 75-155µm, its maximum breadth 124-210µm. Distinguishing characters (rw): This species is distinguished from Cyclampterium ? leptetrum by the coarser meshes of the abdominal wall and generally smaller dimensions of the thorax, and from some Eocene forms, such as Podocyrtis triacantha Ehrenberg and Alacorys tetracantha (Ehrenberg), by the more irregular abdominal wall (and feet, when present) and generally more robust thoracic wall.
As it is defined here, Cyclampterium ? pegetrum includes a wide variety of forms, and later investigation may permit its subdivision into two or more species. Particularly significant in this connection may be an increase in the size of the thorax with time. It is about 85µm long and 140µm wide in specimens from MP 5-1. and about 1 50µm long and 200µm wide in specimens from SDSE 90,104-105 cm. Other possible bases for species distinctions may be the presence or absence of feet, and whether they are terminal or subterminal, and the presence or absence of nodular thickenings on the thoracic wall.

Etymology: From the Greek pegos= strong, and etron=abdomen.

Editors' Notes
Some early representatives of Cyclampterium ? have the abdomen (with meshes smaller than in early specimens of C. ? pegetrum) drawn out distally as three latticed feet. We have found only a few such specimens, and illustrate one as Cyclampterium ? sp. (plate 2, figure 7).


Sanfilippo, A. & Riedel, W. R. (1970). Post-Eocene "closed" theoperid radiolarians. Micropaleontology. 16(4): 446-462. gs


Cyclampterium pegetrum compiled by the radiolaria@mikrotax project team viewed: 24-2-2021

Taxon Search:
Advanced Search

Short stable page link: Go to to create a permanent copy of this page - citation notes

Comments (0)

No comments yet on this page. Please do add comments if you spot any problems, or have information to share

Add Comment

* Required information
Captcha Image
Powered by Commentics