radiolaria - rads_cenozoic - Siphocampe elizabethae

Siphocampe elizabethae

Classification: rads_cenozoic -> Artostrobiidae -> Siphocampe -> Siphocampe elizabethae
Sister taxa: S. acephala, S. altamontensis, S. arachnea, S. bassilis, S. daseia, S. elizabethae, S. grantmackiei, S. imbricata, S. lineata, S. minuta, S. modeloensis, S. nodosaria, S. pachyderma, S. quadrata, S. septata, S. stathmeporoides, S. sp.


Citation: Siphocampe elizabethae (Clark and Campbell 1942)
Rank: species
Basionym: Lithomitra elizabethae Nigrini, 1977
Taxonomic discussion: (Clark and Campbell), 1942, p.92, pl.9, fig.18, as Lithomitra; Nigrini, 1977, p. 256, pl. 3, fig 6

Catalog entries: Lithomitra elizabethae

Original description: Shell small, smooth, with two strictures, generally shaped like a finger-cot and with roughly toothed margin; shell divided into three joints or segments by two horizontal strictures, the apical segment hemispherical (approximately 0.2 total length, distally somewhat flattened, basally limited by a sharp change in length), its sides rather strongly bulging especially in the middle, a little asymmetrical; third segment nearly cylindrical (about the same length as the one above it), its midregion somewhat bulging; apical segment without pores, or at the very most with a single row, perhaps, around the base, and these exceedingly small, middle segment with four tiers of pores, approximately sixteen pores in a row, uniform, oval, well-spaced, double-rimmed, third segment with three tiers of pores, sixteen or more in a row, rows not perfectly horizontal, perhaps 5° off horizontal, pores of different sizes, some much larger than others, ovoidal, elongate, droplet-shaped, or even irregular, those of the apertural row generally smaller and more irregular than others, the apical two rows closer together, the marginal row rather near the aperture; wall comparatively thick, very dark, closely following the shell contour and not modified at the strictures, surface without especial ornamentation, smooth; apertural rim ragged, with small, irregularly shaped, differently sized projections.

Length of shell, 76.0µm; of first segment, 16.6µm; of second and third segments respectively, 30.2µm; breadth of base of primordial segment, 27.6µm; of base of second segment and of apertural margin respectively, 47.4µm; diameter of pores, not over 2.2µm. Distinguishing characters (rw): Lithomitra elizabethae n. sp. differs from the fossil species L. costata, Haeckel (1887), L. punctata, Haeckel (1887) and L. eminens, Haeckel (1887), which have all been described from Sicily, Grotte, and Caltanisette, in having fewer strictures. It is close to L. laevigata Principi (1909) (Quattro Castella) in general shape, but the ultimate segment of that species is relatively longer and has four instead of three tiers of pores. It exhibits no characters which would confuse it with the recent species of the subgenus to which it is assigned.
Remarks on original description: [The authors here lists this species under the subgeneric name Lithomitrissa and include the subgeneric name in the species name.




Biogeography and Palaeobiology

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

Nigrini, C. A. (1977). Tropical Cenozoic Artostrobiidae (Radiolaria). Micropaleontology. 23(3): 241-269. gs


Siphocampe elizabethae compiled by the radiolaria@mikrotax project team viewed: 28-9-2022

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