radiolaria - rads_cat - Sethoconus martini radiolaria - rads_cat - Sethoconus martini

CATALOG OF ORIGINAL DESCRIPTIONS: Sethoconus martini Campbell & Clark 1944

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 -> S -> Sethoconus -> Sethoconus martini
Other pages this level: S. anthocyrtis, S. bimarginatus, S. conicus, S. crinitus, S. dogieli, S. facetus, S. galea, S. hexagonalis, S. hyalinus, S. lophophaena, S. martini, S. myxobrachia, S. orthoceras, S. parvus, S. pileus, S. rayianus, S. reschetnjakae, S. setosus, S. subtilis, S. venosus, S. virgultus, S. woodfordi, S. woodfordi advena

Sethoconus martini

Citation: Sethoconus martini Campbell & Clark 1944
taxonomic rank: species
Described on page(s) : p.44
Type specimens: pl.6, fig.10
Type repository: University of California, Museum of Paleontology, San Francisco
Family (traditional): Actinommidae
Family (modern): Actinommidae

Current identification:

Original Description

Shell bell-shaped, rather large; apical horn stout, vertical, four-bladed, terminally sharp (apically broken in our figured specimens); cephalis small, conical (43°), set off from thorax by an internal septum and externally hardly distinct, its basal diameter about same as its length, and its sides convex; thorax generally subconical (60°) in upper 0.5 and reduced (40°) in lower portion, sides full and change in contour between two sections distinct but not emphatic; shell-aperture badly torn in our specimens, possibly toothed; wall thinner in cephalis than in thorax; surface of cephalis smooth, of thorax, spiny in upper 0.67 where there are thin, needlelike, freely branched and anastomosed nodes of porous framework forming a thorny or cactuslike surface, lower 0.3 smooth, framework of shell a basketlike network enclosing pores, this framework relatively strong (stronger than in recent species in which it is arachnoidal); pores of cephalis tiny, dotlike, probably not more than 50, well separated, single-contoured, shallow, and elliptical, pores of thorax very large, often hexagonal and commonly elliptical, graduated in size to some extent from margin to apex, about a dozen large ones around ultimate part of thorax, and in eight to nine vertical, alternated tiers.

Length (broken), 180µm, of thorax, 110µm; diameter, maximum (broken), 110µm.

No nformation given

Extra details from original publication
Distinguishing characters: Sethoconus martini n. sp. differs from all described species, which are recent, in heavy framework. Recent species (five) have a delicate, spider-weblike framework instead. Yet, martini n. sp. agrees with latter in essential subgeneric characters and should be included in subgenus Plebarachnium [sic] unless, perhaps, heavier framework is a sufficient character to separate it from them. This heavy framework maybe derived from a special mode of life; Haeckel (1887) states that all recent species are surface dwellers.

Editors' Notes
[Campbell and Clark here list the species under the subgeneric name Phlebarachnium and include the subgeneric name in the species name.


Campbell, A. S. & Clark, B. L. (1944). Miocene radiolarian faunas from southern California. Geological Society of America, Special Papers. 51: 1-76. gs


Sethoconus martini compiled by the radiolaria@mikrotax project team viewed: 25-6-2024

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