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1970 Cyclampterium ? leptetrum - Sanfilippo and Riedel Plate 2, figures 11-12
1990 Lophocyrtis (Cyclampterium) leptetrum - Sanfilippo Plate 2, figures 6-9
From Suzuki Paleotax db:
1970 Cyclampterium (?) leptetrum n. sp. Sanfilippo & Riedel p. 456-457, pl. 2, figs. 11-12
1971 Cyclampterium (?) leptetrum Sanfilippo et Riedel Kling p. 1088, pl. 5, figs. 10, 11
1971 Cyclampterium (?) leptetrum Sanfilippo et Riedel Riedel & Sanfilippo p. 1593, pl. 2d, figs. 9-12
1972 Cyclampterium (?) leptetrum Sanfilippo et Riedel Goll p. 958, pl. 22, fig. 1
1972 Cyclampterium leptetrum Sanfilippo et Riedel Johnson & Parker pl. 2, fig. 9
1973 Cyclampterium (?) leptetrum Sanfilippo et Riedel Sanfilippo et al. p. 220, pl. 4, figs. 10-11
1977 Cyclampterium leptetrum Sanfilippo & Riedel Riedel & Sanfilippo pl. 16, fig. 3
1978 Cyclampterium leptetrum Sanfilippo et Riedel Riedel & Sanfilippo p. 67, pl. 4, figs. 12, 13
1978 Cyclampterium leptetrum Sanfilippo et Riedel Theyer et al. pl. 2, fig. 14
1978 Cyclampterium leptetrum Sanfilippo et Riedel Theyer et al. pl. 2, figs. 13
1984 Cyclampterium (?) leptetrum Sanfilippo et Riedel Nigrini & Lombari N95-N96, pl. 22, figs. 2a, 2b
1984 Cyclampterium leptetrum Sanfilippo & Riedel Renz pl. 1, figs. 1-3
1986 Cyclampterium (?) leptetrum Sanfilippo et Riedel Levyikina p. 85, pl. 4, fig. 4
1990 Lophocyrtis (Cyclampterium) leptetrum (Sanfilippo & Riedel) Sanfilippo p. 306, pl. 2, figs. 6-9
Catalog entries: Cyclampterium leptetrum
type material: C. leptetrumOriginal description: Shell generally robust, campanulate to subspherical. Cephalis subspherical, usually poreless but occasionally with a few small pores; thick-walled, especially at the apex. Collar stricture pronounced. Thorax hemispherical or slightly inflated, thick-walled. with subregular circular pores, and a surface which is nodose or, less commonly, only slightly rough or thorny. Abdomen commonly inverted cap-shaped, closed distally, but in some specimens open subcylindrical. Abdominal pores irregular in size and arrangement, generally as large to twice as large as the thoracic pores, generally smaller and more regular than the abdominal pores of C. ? pegetrum. Three to five irregular, subcylindrical, terminal or subterminal feet are present in rare specimens.
Sanfilippo 1990 - Cyclampterium leptetrum (Plate II, 6 9) Remarks: Lophocyrtis ( Cyclampterium ) leptetrum shows a lot of variation in the nature of the thoracic wall and the shape and size of the abdomen. No consistent combination of these two characters with time has yet been found. The hemispherical to inflated thorax can be thickwalled and tuberose(Plate II, 7-9), to thinner walled with a rough or thorny surface. The abdomen may be cylindrical(Plate II, 8 ) or inverted cap-shaped, of varying length(Plate II, 6, 7 ) and with or without feet. L. (C.) leptetrum is distinguished from its ancestor, L. (C.) pegetrum, by the larger dimensions of the thorax, especially its length and by the abdominal pores generally being smaller. From its descendant L. (C.) tanythorax it differs by its shorter thorax. New observations (on 25 specimens from DSDP Site 77B Core 29; Site 289 Cores 45, 46, 54, 59, 62, 64; Site 398D Cores 8, 9 and Site 515B Cores 13, 22 ): total lenth 225-440 µm; length of thorax 150-180 µm, width 170-270 µm, number of pores around the circumference 28-34; length of abdomen 65-220 µm, width 135-310 µm, number of pores around the circumference 12-27. No horn.L. { C.) leptetrum occurs in moderate abundance in the Early Miocene, from its evolutionary origin in the middle of the Cyrtocapsella tetrapera Zone to its transition to L. (C.) tanythorax in the middle of the Calocycletta costata Zone.
Published descriptions
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:
Sanfilippo, A. & Riedel, W. R. (1970). Post-Eocene "closed" theoperid radiolarians. Micropaleontology. 16(4): 446-462. gs Sanfilippo, A. (1990). Origin of the subgenera Cyclampterium, Parampterium and Sciadiopeplus from Lophocyrtis (Lophocyrtis) (Radiolaria, Theoperidae). Marine Micropaleontology. 15(3-4): 287-312. gsReferences:
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Lophocyrtis leptetrum compiled by the radiolaria@mikrotax project team viewed: 9-9-2024
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