Catalog entries: Calocycletta caepa
Original description: Cephalis ovate, lobed, with sparse circular to subcircular pores and bearing a conical (early forms) to slightly bladed (late forms) apical horn. Thorax subspherical to campanulate, with circular pores hexagonally arranged and longitudinally aligned. External lumbar stricture absent in early forms but distinct in late forms. Abdomen lighter and more delicate than thorax, cylindrical in shape, containing subcircular to circular pores which may show longitudinal alignment and hexagonal arrangement (early forms). Late forms may have a very light, very irregularly pored abdomen that appears almost spongy. Abdomen terminates in five to fourteen triangular or spike-shaped feet which are usually very short and irregularly spaced.
Based on 30 specimens. Length of apical horn 62-130 µ, of cephalis 34-43 µ, of thorax 62-110 µ, of abdomen 43-158 µ, of feet 5-14 µ. Breadth of cephalis 34-43 µ, of thorax 101-134 µ, of abdomen (distally) 58-101 µ. Distinguishing characters (rw): Only if the abdomen and terminal feet are preserved can early forms of C. caepa be distinguished from C. virginis and C. serrata. The bladed apical horn, campanulate thorax and very delicate abdomen of later forms aid in their distinction. Phylogeny (rw): C. caepa evolved from Calocycletta virginis near the Early to Middle Miocene boundary and Calocycletta (Calocyclior) caepa Moore continued on into the Late Miocene. It left no descendants. For generic level phylogeny see Sanfilippo and Riedel, 1992, p.31
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:
Moore, T. C. Jr. (1972). Mid-Tertiary evolution of the radiolarian genus Calocycletta. Micropaleontology. 18(2): 144-152. gs Riedel, W. R. & Sanfilippo, A. (1978b). Stratigraphy and evolution of tropical Cenozoic radiolarians. Micropaleontology. 24(1): 61-96. gs
Moore, T. C. Jr. (1972). Mid-Tertiary evolution of the radiolarian genus Calocycletta. Micropaleontology. 18(2): 144-152. gs
Riedel, W. R. & Sanfilippo, A. (1978b). Stratigraphy and evolution of tropical Cenozoic radiolarians. Micropaleontology. 24(1): 61-96. gs
Calocycletta caepa compiled by the radiolaria@mikrotax project team viewed: 4-12-2022
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