Theocotyle conica

Classification: rads_cenozoic -> Theoperidae -> Theocotylidae -> Theocotyle -> Theocotyle conica
Sister taxa: T. conica, T. cryptocephala, T. nigriniae, T. venezuelensis, T. sp.,


Citation: Theocotyle conica Foreman 1973
Rank: species
Basionym: Theocotyle conica
Notes & discussion: Foreman 1973 p.440 pl.4 fig.11;pl.12 figs.19-20; Sanfilippo & Riedel 1982 p.177; Sanfilippo et al.1985 p.683 fig.25.3

Catalog entries: Theocotyle cryptocephala conica

Original description: Shell as for late forms of Theocotyle (Theocotyle) cryptocephala cryptocephala (?) except that the abdomen is distinctly conical in shape and the vestigal wings of T. (T.) cryptocephala cryptocephala (?) are sometimes entirely lacking; abdominal pores may be up to twice as large as those of the thorax.

(Based on ten specimens) Length overall, exclusive of horn, 130-175µm,of thorax 35-45µm, of abdomen 85-100µm; greatest width of abdomen 115-135µm. Distinguishing characters (rw): This species in general form resembles that of Theocotyle (Theocotylissa) ficus but differs from the specimens with which it cooc-curs by its smaller size, and from the early small specimens of the latter whose size might coincide with those of T. (T.) cryptocephala (?) conica by the more ovate form of T. (Theocotylissa) ficus. It differs from its ancestor T (F) cryptocephala cryptocephala (?) in the conical shape of the abdomen. Its relationship to T. (T.) venezuelensis is not understood. Phylogeny (rw): This form appears to have evolved directly from T. (T.) cryptocephala cryptocephala (?) with the early forms of T. (T.) cryptocephala (?) conica still retaining the vestigial wings.


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:


Foreman, H. P. (1973a). Radiolaria of Leg 10 with systematics and ranges for the families Amphipyndacidae, Artostrobiidae, and Theoperidae. Initial Reports of the Deep Sea Drilling Project. 10: 407-474. gs :: ::

Sanfilippo, A. & Riedel, W. R. (1982). Revision of the radiolarian genera Theocotyle, Theocotylissa and Thyrsocyrtis. Micropaleontology. 28(2): 170-188. gs :: ::

Sanfilippo, A., Westberg-Smith, M. J. & Riedel, W. R. (1985). Cenozoic Radiolaria. In, Bolli, H. M. , Saunders, J. B. & Perch-Nielsen K. (eds) Plankton Stratigraphy. Cambridge University Press, Cambridge 631-712. gs :: ::


Theocotyle conica compiled by the radiolaria@mikrotax project team viewed: 6-7-2020

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