Stylodictya targaeformis

Classification: rads_cenozoic -> Spongodiscidae -> Stylodictyidae -> Stylodictya -> Stylodictya targaeformis
Sister taxa: S. aculeata, S. gracilis, S. hastata, S. inaequalispina, S. multispina, S. ocellata, S. orbiculata, S. rosella, S. stellata, S. tainemplekta, S. targaeformis, S. tenuispina, S. validispina, S. sp.


Citation: Stylodictya targaeformis (Clark and Campbell 1942)
Rank: species
Basionym: Staurodictya targaeformis Clark & Campbell 1942
Taxonomic discussion: (Clark & Campbell) 1942; Petrushevskaya and Kozlova 1972

Catalog entries: Staurodictya targaeformis

Original description: Disc circular but tending to be somewhat four-sided, the interradii being flattened, with four strong marginal spines in two opposite pairs, cylindrical for most of their length, needle-like, tips are broken, bases slightly expanded, four-angled proximally and with minute, backwardly directed hooklets above the base; all of the seven rings, concentric, annular, flattened in the interradii, the rings gradually decreasing in breadth form the periphery to the center, the earliest ring about half the breadth of the distalmost one, the rings divided into four almost equal quadrants by two periradial constrictions whch are perpendicular to each other, the constrictions very slight and hardly showing in the photograph, the pores regularly circular, very small, two or three on the breadth of a ring, the peripheral ones larger than those of the central region and gradually and regularly increasing in size from the center outward; margin of the interradii denticulate.

Diameter of disc, 170µm; of pores, 2.2-4.4µm; width of bands, 8.8-14.4µm. Distinguishing characters (rw): The disc is much like that of S. elegans Haeckel (1887), but the spines are not so elaborate as in the species. The spines are apparently longer than those of S. quadrispina Haeckel (1887). The rings are of unequal breadth in contrast to those of S. medusa Haeckel (1887) and S. ciliata Haeckel (1887), which are equal throughout.
Remarks on original description: [The authors here list this species under the subgeneric name Staurodictyon and include the subgeneric name in the species name.


Biogeography and Palaeobiology

Similar species: targaeformis

Biostratigraphic distribution

Geological Range:
Last occurrence (top): within Paleogene Period (23.03-66.04Ma, top in Chattian stage). Data source: Lazarus et al. 2015 - "P age group"
First occurrence (base): within Paleogene Period (23.03-66.04Ma, base in Danian stage). Data source: Lazarus et al. 2015 - "P age group"

Plot of occurrence data:


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

Petrushevskaya, M. G. & Kozlova, G. E. (1972). Radiolaria: Leg 14, Deep Sea Drilling Project. Initial Reports of the Deep Sea Drilling Project. 14: 459-648. gs


Stylodictya targaeformis compiled by the radiolaria@mikrotax project team viewed: 25-10-2020

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