Catalog entries: Phormospyris stabilis capoi
Benson 1966 - Phormospyris stabilis capoi Smooth, bilocular cephalis with a distinct, broad, V-shaped sagittal constriction in its upper surface and a skirt-like partial latticed thorax developed between 6-13 (generally 8-9) straight to slightly convex outward, downward divergent, cylindrical to conical feet or foot-like spines. Dorsal edge of upper face of cephalis on either side of the sagittal constriction straight, laterally ascending, as in Ceratospyris cf. pentagona Ehrenberg, consisting of a pair of lateral bars originating from the base of the thin, conical apical spine and extending as conical lateral spines (horns in the sense of Haeckel); ventral edge of upper face of cephalis in a few specimens with a similar pair of straight, laterally ascending bars continuing as lateral spines. Pores of cephalis of variable shapes and sizes, generally subcircular to elliptical, one-half to five times the width of the intervening bars; paired pores separated by the sagittal ring generally larger--two pairs on the dorsal face the largest, the lower pair the larger of the two, 2-3 pairs on the upper face, and 3-4 pairs on the ventral face. Sagittal ring asymmetrical, three-bladed with one blade extending outward in the sagittal plane and two blades extending laterally inward. Apical spine extends from the straight, vertical apical bar of the sagittal ring; a short thorn-like vertical spine is present. Cardinal and cervical pores similar in shape and size to those of Patagospyris? sp.; a pair of pores between the secondary lateral bars at the base of the cephalis and the dorsal spine are present in the dorsal proximal part of the skirt-like thoracic lattice; these correspond to external jugular pores. The feet originate from the collar ring, are variable in number but generally equally spaced; three of the feet correspond to the dorsal and primary lateral bars originating from the short cylindrical median bar; the secondary lateral bars extend laterally as short, conical, horizontal spines which arise from the dorso-lateral corners of the collar stricture. Measurements: based on 30 specimens from stations 92, 93, and 106: sagittal height of cephalis 35-46 m, maximum breadth 58-101 µm, length of skirt-like thoracic lattice 27-74 µm, of free portion of foot-like spines 6-62 µm; maximum lateral breadth between foot-like spines 68-135 µm; length of apical spine 1-68 µm, of the pair of lateral spines (horns) of the cephalis 6-70 :m. Remarks: This species agrees well with the definition of the genus Rhodospyris Haeckel (1882, p. 443; 1887, pp. 1088-1089) in the presence of at least three spines arising from the upper surface of the cephalis (three apical horns sensu Haeckel), a thorax at least partially developed, and numerous (9-12 or more) basal feet or foot-like spines. It cannot be identified with either of the two species of this genus described by Haeckel (1887, p. 1089) and, therefore, may be a new species. It is similar in some aspects to Anthospyris mammillata Haeckel (1887, p. 1064, Pl. 87, fig. 15), but this species does not have a partially developed thorax between the feet. Without first studying Haeckel's type rnaterial the recognition of the Gulf species as a new species is in doubt; therefore, a new name is not proposed for this taxon. Distribution: This species is rare but cosmopolitan in the Gulf, occurring as far north as station 192.It is absent at stations 64, 130, 191, 194, and those to the north. Its distribution is similar to that of Patagospyris? sp.; therefore, it is able to inhabit both oceanic and Gulf waters but does not thrive in nearshore or shelf environments. \ From: Benson, 1966, p. 329-331; pl. 23, figs. 3-5:Rhodospyris sp.
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:
Benson, R. N. (1966). Recent Radiolaria from the Gulf of California. Thesis, Minnesota University. 1-577. gs Benson, R. N. (1983). Quaternary radiolarians from the Mouth of the Gulf of California, Deep Sea Drilling Project Leg 65. Initial Reports of the Deep Sea Drilling Project. 65: 491-523. gs Bjørklund, K. R. & de Ruiter, R. (1987). Radiolarian preservation in eastern Mediterranean anoxic sediments. Marine Geology. 75: 271-281. gs Danelian, T. & Frydas, D. (1998). Late Quaternary polycystine radiolarians and silicoflagellates of a diatomaceous sapropel from the Eastern Mediterranean, Sites 969 and 971. Proceedings of the Ocean Drilling Program, Scientific Results. 160: 137-154. gs O De Wever, P., Caulet, J. P. & Bourgois, J. (1990b). Radiolarian biostratigraphy from Leg 112 on the Peru margin. Proceedings of the Ocean Drilling Program, Scientific Results. 112: 181-207. gs Goll, M. R. (1976). Morphological intergradation between modern populations of Lophospyris and Phormospyris (Trissocyclidae, Radiolaria). Micropaleontology. 22(4): 379-419. gs Takahashi, K. (1991). Radiolaria: Flux, ecology, and Taxonomy in the Pacific and Atlantic. Ocean Biocoenosis Series. 3: 1-301. gs Missing or ambiguous references: Dumitrica 1972; References:

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Tholospyris capoi compiled by the radiolaria@mikrotax project team viewed: 16-11-2025
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