- Type images:
type material: L. audax
From Suzuki Paleotax db:
1953 Lychnodictyum audax n. sp. Riedel p. 810-811, pl. 85, fig. 9
1957 Lychnodictyum audax Riedel Riedel p. 81
1961 Lychnodictyum audax Riedel Bachmann pl. 2, fig. 19
1974 Lychnodictyum audax Riedel Sanfilippo & Riedel p. 1022-1023, pl. 2, fig. 8
1977 Lychnodictyum audax Riedel Riedel & Sanfilippo pl. 12, fig. 8
1978 Lychnodictyum audax Riedel Riedel & Sanfilippo p. 115, pl. 4, fig. 17
1978 Lychnodictyum audax Riedel Riedel & Sanfilippo p. 71, pl. 7, fig. 5
1978 Lychnodictyum audax Riedel Weaver & Dinkelman pl. 2, fig. 1
1980 Lychnodictyum audax Riedel Sakai p. 711, pl. 8, figs. 16a, 16b
1984 Lychnodictyum audax Riedel Nigrini & Lombari N123-124, pl. 25, fig. 1
1985 Lychnodictyum audax (Riedel) Sanfilippo et al. p. 677-678, fig. 21.2
1985 Pterocanium audax (Riedel) Lazarus et al. p. 202-204, fig. 19.1-19.4, 20.1, 20.2
1988 Lychnodictyum audax Riedel Sanfilippo p. 175, pl. 1, fig. 20
1989 Pterocanium audax (Riedel) Alexandrovich pl. 4, fig. 7
1993 Lychnodictyum audax Riedel Sharma & Singh pl. 3, figs. 6, 7
Catalog entries: Lychnodictyum audax
type material: L. audaxOriginal description: Shell campanulate, with rough surface and distinct collar stricture. Length of the two joints 1:4, breadth 1:5. Cephalis subspherical, with rather few, subcircular, well-separated pores, bearing a conical horn of the same to twice the length, which has short, obtusely conical protuberances in its distal portion. Thorax subglobular, with rough ridges between the large rounded pores, which are 2 - 5 times as broad as the intervening bars. Peristome constricted, the feet arising slightly above the margin. Feet of approximately the same length as the thorax, triangular pyramidal with pronounced blades, fenestrated in the proximal portion, almost straight, divergent. Small spines are often present on the lower edge of the thorax as if remnants from a reduced abdomen.
Remarks on original description: This two-segmented theoperid has a campanulate, rough-surfaced shell, three divergent, bladed legs which are fenestrated proximally, and a stout horn which is thorny distally. Occasionally, remnants of a skirt of Lychnodictyum audax Riedel meshwork hangs from the peristome. Some specimens from high latitude sites have thorns on the surface of the thorax, and poorly developed protuberances on the horn. (Sanfilippo et al. 1985)
Although this species is evidently closely related to stratigraphically useful forms such as Pterocanium prismatium, it is not now transferred to that genus because of uncertainty regarding the nature of the figured type species of Pterocanium (Lithocampe aculeata Ehrenberg, according to Foreman and Riedel, 1972). (Sanfilippo and Riedel, 1974)
We agree in principle with Lazarus et al., 1985 that Lychnodictyum audax and its probably descendant, Pterocanium trilobum (see Nigrini, 1967, p.71, pl.7, figs.3a-3b) belong in the same genus. However, since L. audax may well be the ancestral stock, we hesitate to use their synonym until the entire lineage has been examined. (Caulet et al., 1993)
Geological Range:
Last occurrence (top): within Neogene Period (2.59-23.03Ma, top in Piacenzian stage). Data source: Lazarus et al. 2015 - "N age group"
First occurrence (base): within Neogene Period (2.59-23.03Ma, base in Aquitanian stage). Data source: Lazarus et al. 2015 - "N age group"
Plot of occurrence data:
Alexandrovich, J. M. (1989). Radiolarian biostratigraphy of ODP Leg 111, Site 677, eastern equatorial Pacific, late Miocene through Pleistocene. Proceedings of the Ocean Drilling Program, Scientific Results. 111: 245-262. gs Lazarus, D., Scherer, R. P. & Prothero, D. R. (1985). Evolution of the radiolarian species-complex Pterocanium: A preliminary survey. Journal of Paleontology. 59(1): 183-220. gs Riedel, W. R. (1953). Mesozoic and Late Tertiary Radiolaria of Rotti. Journal of Paleontology. 27(6): 805-813. gsReferences:
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Pterocanium audax compiled by the radiolaria@mikrotax project team viewed: 22-7-2026
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