Stylodictya aculeata

Classification: rads_cenozoic -> Spongodiscidae -> Stylodictyidae -> Stylodictya -> Stylodictya aculeata
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 aculeata Jørgensen 1905
Rank: species
Basionym: Stylodictya aculeata
Taxonomic discussion: Jorgensen, 1905; Nigrini & Lombari 1984 S69 Pl.10 Fig 1.

Catalog entries: Stylodictya aculeata

Original description: Shape of the shell in side view: Broadly linear, with rounded corners and ends. From the centre to near the margin, there are small scattered punctiform byspines. System of the rings: On the whole like the preceding, only the rings are more irregular in shape and width. Outside the fourth ring there seems to be traceable the beginning of a 5th which is as yet not formed.;On the whole like those of the preceding. Very large pores here and there on the edge of the disc, which would probably have formed several smaller ones later on. The byspines are very scattered, fewer in number than in the preceding species, but distributed over a larger part of the disc. Radial spines The rings are united similarly to those in the preceding species, but the number of radial spines around the disc is larger, more than 30. The spines are narrower and more irregularly developed, some being a little bent, turned outwards and obliquely upwards, not all at the same level, equatorial, but distributed over the broad, rounded margin of the disc. The length of the spines is about the same as in the preceding species. Byspines: Very similar to those of the preceding species, but more scattered and distributed over the whole of the disc nearly out to the margin.

The diameter of the inmost shell 12µm, of the first ring about 38, of the second 54, of the third 85, of the fourth 110. Pores uneven, most of them being 2-4µm. The spines protrude as much as to 30µm. The disc is 28µm in thickness. Distinguishing characters (rw): This species corresponds well in structure to the foregoing one [Stylodictya validispina], but differs in a marked degree with regard to its radial spines, which are particularly numerous, and are more irregularly placed, not all lying at the same level, that of the disc, but pointing obliquely beyond and beneath it. This form appears to differ considerably from the other species on account of the irregularly placed marginal spines. The specimen illustrated is probably not quite fully developed.
Remarks on original description: [The preceding species is Stylodictya validispina]


Biogeography and Palaeobiology

Biostratigraphic distribution

Geological Range:
Last occurrence (top): Extant Data source: Lazarus et al. 2015 - "R age group"
First occurrence (base): within Quaternary Period (0.00-2.59Ma, base in Gelasian stage). Data source: Lazarus et al. 2015 - "R age group"

Plot of occurrence data:


Jørgensen, E (1905). The protist plankton and diatoms in bottom samples: Radiolaria. In, Nordgaard (ed.) Hydrographical and biological investigation in Norwegian Fjord. 49-151. gs

Nigrini, C. A. & Lombari, G. (1984). A guide to Miocene Radiolaria. Cushman Foundation for Foraminiferal Research, Special Publication. 22: 1-206. gs


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

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