Catalog entries: Amphitholus acanthometra
Original description: Central chamber about twice as broad and as high as both cupolas. On the surface quite symmetrically distributed twenty long and strong cylindrical radial spines; eight in the sagittal plane or in the meridian plane of the central chamber (four opposite in pairs in the principal and the sagittal axes, four others in the middle between the principal and the sagittal spines); four in the horizontal transverse plane, on both sides of the poles of the major or lateral axis; and eight in diagonal planes (corresponding to the eight wing-spines of Tetrapyle octacantha). In the centre of the central chamber is a distinct trizonal medullary shell like that of Tetrapyle, with two vertical columella beams. Pores of the cortical shell subregular, circular, with elevated hexagonal frames, about four times as broad as the bars; five to seven in the semicircle of one cupola. (This remarkable species differs from Tholartus vicenus in the possession of a medullary shell, from Amphitholonium acanthometra by the simple cortical shell. Compare these species).
Remarks on original description: Haeckel listed Amphitholus acanthometra under the subgeneric name Amphitholura, but did not include the subgeneric name in the species name.
In the description, the species name Amphitholonium acanthometra is not know. Haeckel here probably intends Amphitholonium acanthonium.[comment from RadWorld database]
Last occurrence (top): Extant. Data source: Lazarus et al. 2015 - "R age group"
First occurrence (base): within Quaternary Period (0.00-2.59Ma, base in Gelasian stage). Data source: Lazarus et al. 2015 - "R age group"
Plot of occurrence data:
Amphitholus acanthometra compiled by the radiolaria@mikrotax project team viewed: 2-7-2022
Short stable page link: https://mikrotax.org/radiolaria/index.php?id=203109 Go to Archive.is to create a permanent copy of this page - citation notes