A probably polyphyletic group which has been divided using sometimes incompatible criteria into numerous subgroups by various authors. Many proposed divisions are based on rather arbitrary characters, and may not be any more natural than many of those included in Haeckel's highly artificial taxonomy. For example Ethmosphaeridae, a category of Haeckel for forms with no 'major' external spines is included in many modern classifications but shows virtually no molecular differences to a genus (Cladococcus) with substantial external spines [Biard et al. 2022]. Thus only a selection of proposed new families included here, mostly for the practical purpose of navigating the high diversity of the group, but these should be seen as highly provisional. - dl
Catalog entries: Actinommidae
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Published descriptions
Lazarus et al. 2021-
Spherical to ellipsoidal radiolarians with one or more mostly concentric lattice shells, connected by radial beams, sometimes with radial external spines.
Geological Range:
Last occurrence (top): Extant. Data source: Total of ranges of the species in this database
First occurrence (base): within Paleogene Period (23.03-66.04Ma, base in Danian stage). Data source: Total of ranges of species in this database
Plot of occurrence data:
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Actinommidae compiled by the radiolaria@mikrotax project team viewed: 12-5-2026
Short stable page link: https://mikrotax.org/radiolaria/index.php?id=203036 Go to Archive.is to create a permanent copy of this page - citation notes |