radiolaria - rads_cenozoic - Theocyrtis annosa radiolaria - rads_cenozoic - Theocyrtis annosa

Theocyrtis annosa

Classification: rads_cenozoic -> Pterocorythidae -> Theocyrtis -> Theocyrtis annosa
Sister taxa: T. annosa, T. careotuberosa, T. diabloensis, T. litos, T. perpumila, T. perysinos, T. robusta, T. setanios, T. tuberosa, T. sp.


Citation: Theocyrtis annosa (Riedel 1959)
taxonomic rank: species
Basionym: Phormocyrtis annosa Riedel 1959
Taxonomic discussion: (Riedel) 1959; Riedel and Sanfilippo 1970

Catalog entries: Phormocyrtis annosa

Original description: Cephalis elongate, lobate, with a few small pores, surmounted by a stout three-bladed horn. Thorax inflated-campanulate, with regular circular pores. Thoracic wall pronouncedly plicate longitudinally, the plicae being separated by three to five longitudinal rows of pores. Abdomen subcylindrical, with a thinner wall than the thorax, and sub-circular to circular pores usually less regularly arranged than in the thorax. In most specimens the thoracic plicae extend into the abdomen, where they become less distinct. Termination of the abdomen usually ragged, but in some specimens with approximately eight to fifteen parallel, triangular lamellar feet or teeth. This species differs from all others of the genus in having a thick-walled, pronouncedly plicate thorax.


Biogeography and Palaeobiology

Similar species


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:


Riedel, W. R. & Sanfilippo, A. (1970). Radiolaria, Leg. 4 DSDP. Initial Reports of the Deep Sea Drilling Project. 4: 503-575. gs

Riedel, W. R. (1959a). Oligocene and Lower Miocene Radiolaria in tropical Pacific sediments. Micropaleontology. 5(3): 285-302. gs


Theocyrtis annosa compiled by the radiolaria@mikrotax project team viewed: 18-5-2024

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