Stephanastrum quadratum, from Haeckel (1899–1904).

Belongs within: Stauraxonaria.

The Larnacillioidea are a group of radiolarians known from the Late Cretaceous (Cenomanian) to the present. Representatives have skeletons with two oppositely positioned gates, opened laterally in opposite directions, and the initial frame is heteropolar (Afanasieva et al. 2005).

    |    |--Tholocubus Haeckel 1887AA05
    |    `--Tholonium Haeckel 1887AA05
         |    |--Coccolarnacium Dumitrica 1989AA05
         |    |--Cryptolarnacium Dumitrica 1989AA05
         |    `--Spongopyle Dreyer 1889AA05
         |    |--Plectodiscus Kozlova 1972AA05
         |    `--Circodiscus Kozlova 1972AA05
         |         `--C. microporusAA05
         |    |--Larnacilla Haeckel 1887AA05
         |    |--Larnacopylomma Dumitrica 1989AA05
         |    `--Phorticium Haeckel 1881AA05
         |         `--P. clevei (Jørgensen 1900)BC98
              |--Amphimenium Haeckel 1881AA05
              |--Stauralastrum Haeckel 1887AA05
              |--Histiastrum Ehrenberg 1847 (see below for synonymy)AA05
              |    `--H. boseanumH04
              `--Stephanastrum Ehrenberg 1847AA05
                   `--S. quadratumH04

Histiastrum Ehrenberg 1847 [incl. Histiastrella Haeckel 1887, Histiastromma Haeckel 1887, Histigiastrum Levikina 1986, Tessarastrella Haeckel 1887, Tessarastromma Haeckel 1887, Tesserastrum Haeckel 1887]AA05

*Type species of generic name indicated


[AA05] Afanasieva, M. S., E. O. Amon, Y. V. Agarkov & D. S. Boltovskoy. 2005. Radiolarians in the geological record. Paleontological Journal 39 (Suppl. 3): S135–S392.

[BC98] Bjørklund, K. R., G. Cortese, N. Swanberg & H. J. Schrader. 1998. Radiolarian faunal provinces in surface sediments of the Greenland, Iceland and Norwegian (GIN) Seas. Marine Micropalaeontology 35: 105–140.

[H04] Haeckel, E. 1899–1904. Kunstformen der Natur. Bibliographisches Institut: Leipzig und Wien.

Leave a comment

Your email address will not be published. Required fields are marked *