CATALOG OF ORIGINAL DESCRIPTIONS: Lithatractus hederae 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 -> L -> Lithatractus -> Lithatractus hederae
Other pages this level: L. birostratus, L. carduelis, L. cirsium, L. conifer, L. conostylus, L. convallaria, L. echiniscus, L. floridus, L. fragilis, L. gamoporus, L. hederae, L. hexagonalis, L. jugatus, L. leptostylus, L. lobatus, L. miocaenica, L. nucleolus, L. nuphar, L. pachystylus, L. pierinae, L. pterosphaerus, L. rosetta, L. santaeannae, L. santaeannae pusillus, L. timmsi, L. timmsi quadrispinus

Lithatractus hederae

Citation: Lithatractus hederae Clark & Campbell 1942
Rank: species
Type specimens: pl.5, fig.3
Type repository: University of California, Museum of Paleontology, San Francisco
Described on page(s) : p.33
Family (traditional): Actinommidae
Family (modern): Stylosphaeridae

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Current identification:

Original Description
Shell ovate, with two short, opposite polar spines, these spines conical, four-angled, with slightly concave interfaces for some distance along their length, relatively short, having the same length as the longer axis of the medullary shell or longer (in the figured specimen), their bases wider than the diameter of a cortical pore; cortical shell subcircular, only a trifle (0.1) longer than wide, surface smooth, with six pores across the equator and nine from pole to pole, pores subequal, strongly subhexagonal, with thick bars and dense framework; medullary shell very strongly ovate, with six pores across the equator and almost twice as many from pole to pole, these pores mostly subhexagonal, bars thin, with six supporting beams at right angles to each other, four equatorial and two polar.

Length of polar spines, 67.2µm (41.8µm in an unfigured specimen); diameter of cortical shell, 92.4 and 81.4µm respectively for the two axes, of medullary shell, 44 and 41.8 µm respectively for the two axes; wall thickness 8.8µm. Distinguishing characters (rw): Lithatractus hederae n. sp. has shorter polar spines than L. hexagonalis Haeckel (1887) and a smaller cortical shell than L. leptostylus Haeckel (1887), L. pachystylus Haeckel (1887), and L. convallarus Haeckel (1887).

Editors' Notes
The authors here list this species under the subgeneric name Lithatractaria and include the subgeneric name in the species name.


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


Lithatractus hederae compiled by the radiolaria@mikrotax project team viewed: 20-4-2021

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