radiolaria - rads_cat - Heliodiscus hexasteriscus radiolaria - rads_cat - Heliodiscus hexasteriscus

CATALOG OF ORIGINAL DESCRIPTIONS: Heliodiscus hexasteriscus 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 -> H -> Heliodiscus -> Heliodiscus hexasteriscus
Other pages this level: H. apollinis, H. asteriscoides, H. asteriscus, H. charlestonensis, H. cingillium brevispina, H. cingillum, H. cingillum brevispina, H. echiniscus, H. glyphodon, H. grottensis, H. heliasteriscus, H. hexasteriscus, H. inca, H. lentis, H. linckiaformis, H. marginatus, H. ninae, H. pentasteriscus, H. perplexus, H. pertusus, H. polymorphus, H. quadratus, H. saturnalis, H. saturnalis [junior homonym], H. saturnalis jh, H. siculus, H. solaster> >>

Heliodiscus hexasteriscus

Citation: Heliodiscus hexasteriscus Clark & Campbell 1942
taxonomic rank: species
Described on page(s) : p.40
Type specimens: pl.3, figs.14, 15
Type repository: University of California, Museum of Paleontology, San Francisco
Family (traditional): Heliodiscidae
Family (modern): Heliodiscidae

Current identification/main database link: Heliodiscus hexasteriscus Clark & Campbell 1942

Original Description

Shell like a sunburst with six rays of moderate length, equal in size except as broken, about half the diameter of the cortical shell in length, strongly four-angled in the lower three-fourths and rounded distally; tips bluntly pointed, the bases flaring to the disc; hyaline, and with short, backwardly directed processes or hooklets in the proximal part, these evidently the places of attachment of contractile protoplasmic myonemes; cortical shell lenticular, biconvex, with small, regular, equal circular pores, the pores with thin, raised rims or collars and with very minute, rarely bifurcate, mostly simple, sepaloid spinules, about twenty pores or more in a radius, and from five to nine around the edge on an interradius; cavity of the pores cylindrical, asymmetrically pointed toward the center of the disc, wall thick; medullary shell obscured by the extreme density of the cortical wall.

Diameter of cortical shell, 160µm; of pores, 8.8µm; length of spines, 78.2µm; width of wall, 12.2µm; of spine above the flaring base, 18.8µm.

Greek hexa- + astericus -i = six star mark(s)

Extra details from original publication
Distinguishing characters: A second specimen (Pl. 3, fig. 14) has a somewhat larger cortical shell (180µm) and its medullary shell is clear-cut (43µm). The spines are all broken and not subequidistant as int he more complete specimen. The spines, also, are thinner and less flaring at the base.
Heliodiscus heliasteriscus n. sp. differs from H. pentasteriscus n. sp. in its small disc (160 as against 200µm) and, also, has six instead of five spines, these last not strictly equidistant and forming a line of symmetry as in the five-rayed species.

Editors' Notes
[The authors here list Heliodiscus hexasteriscus under the subgeneric name Heliodiscetta and include the subgeneric name in the species name.


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


Heliodiscus hexasteriscus compiled by the radiolaria@mikrotax project team viewed: 19-6-2024

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