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Hexalonche philanahedra Blueford, 1982

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Description: Two concentric shells, 90-110 and 24-30 Ám in diameter. Outer shell generally thin, smooth, occasionally thorny or rough. Six spines, pyramidal with convex edges, equal 36 Ám in length. Five to seven spines not uncommon. Pores nearly equal,slightly elliptical, 5-8 Ám in diameter, closely packed, polygonally framed, 7-11 Ám between their centers. Six thick radial beams connecting inner to outer shell. Surface smooth to rough. Pores equal, elliptical or hexagonal, closely packed, polygonally framed.
Holotype: Plate 4, figures 9a-b, DSDP Site 77, section B-9, core 6, 50-52 cm, England finder G 25/4 (USNM 315058).
Distinguishing features: Two shells with thin, smooth surface and roundish pores. Six equal spines, pyramidal with convex edges.
Comments: Haeckel described three species that are similar to this species, but none fully conforms to it. Hexalonche philosophica has short conical spines and less regular pores. Hexalonche anaximadri is covered with spines and has surface pores that are hexagonal. Hexalonche octahedra has circular pores on its inner shell and longer spines. Following H. philanahedra from the late Miocene to Holocene may show that this species is ancestral to those Haeckel described.
Derivation of name: Combination of syllables from H. philosophica, H.anaximadri and H.octahedra.
Occurance: Moderatly abundant except in the lower sections where individuals are rare. Smaller specimens in slide 23, Site 77B and slide 46, Site 289 may represent an evolutionary event.
Blueford 1982


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