Radiolaria Fossil range: Cambrian - Recent
Plate from Ernst Haeckel's 1904 Kunstformen der Natur (Artforms of Nature), showing radiolarians belonging to the superfamily Stephoidea.
Scientific classification
Domain: Eukaryota (unranked) Rhizaria Phylum: Radiolaria Müller 1858 emend.
Classes
Polycystinea Acantharea Sticholonchea The Cambrian is a major division of the geologic timescale that begins about 542 ± 1. ... Image File history File links Download high resolution version (2320x3292, 1745 KB) Summary The 71st plate from Ernst Haeckels Kunstformen der Natur (1904), showing Radiolarians of the order Stephoidea. ... Ernst Haeckel. ... Wikimedia Commons has media related to: Kunstformen der Natur Kunstformen der Natur (Artforms of Nature) is a book of lithographic prints by German biologist Ernst Haeckel. ... Scientific classification or biological classification is a method by which biologists group and categorize species of organisms. ... Kingdoms Animalia - Animals Fungi Plantae - Plants Protista Alternative Phylogeny Unikonta    Opisthokonta    Amoebozoa Bikonta    Apusozoa    Cabozoa       Rhizaria       Excavata    Corticata       Archaeplastida       Chromalveolata Animals, plants, fungi, and protists are eukaryotes (IPA: ), organisms with a complex cell or cells, where the genetic material is organized into a membrane-bound nucleus or nuclei. ... The Rhizaria are a major line of protists. ... Fritz Müller Johann Friedrich Theodor Müller (March 31, 1821–May 21, 1897) was a German biologist who emigrated to Brazil, where he studied the natural history of the Amazon Rainforest and was an early advocate of evolutionary theory. ... The polycystines are a group of radiolarian protists. ... The Acantharea are a small group of radiolarian protozoa, distinguished mainly by their skeletons. ... Sticholonche is a peculiar genus of protozoan with a single species, , found in open oceans at depths of 100-500 metres. ...

Radiolarians (also radiolaria) are amoeboid protozoa that produce intricate mineral skeletons, typically with a central capsule dividing the cell into inner and outer portions, called endoplasm and ectoplasm. They are found as zooplankton throughout the ocean, and because of their rapid turn-over of species, their tests are important diagnostic fossils found from the Cambrian onwards. Some common radiolarian fossils include Actinomma, Heliosphaera and Hexadoridium. Amoeba (Chaos diffluens) Foraminiferan (Ammonia tepida) Heliozoan (Actinophrys sol) Amoeboids are cells that move or feed by means of temporary projections, called pseudopods (false feet). ... Wikisource has an original article from the 1911 Encyclopædia Britannica about: Protozoa Protozoa (in Greek proto = first and zoa = animals) are single-celled eukaryotes (organisms whose cells have nuclei) that commonly show characteristics usually associated with animals, most notably mobility and heterotrophy. ... Minerals are natural compounds formed through geological processes. ... This article does not cite its references or sources. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hook from Micrographia which is the origin of the word cell. Cells in culture, stained for keratin (red) and DNA (green). ... The inner, more fluid layer in a cell. ... An ectoplasm (ghost) In cell biology, ectoplasm (outer plasma) refers to the outer regions of the cytoplasm of a cell. ... Photomontage of plankton organisms Plankton is the aggregate community of weakly swimming but mostly drifting small organisms that inhabit the water column of the ocean, seas, and bodies of freshwater. ... Three small ammonite fossils, each approximately 1. ... The Cambrian is a major division of the geologic timescale that begins about 542 ± 1. ...

Description

Radiolaria illustration from the Challenger Expedition 1873-76.

Radiolarians have many needle-like pseudopodia supported by bundles of microtubules, called axopods, which aid in flotation. The nuclei and most other organelles are in the endoplasm, while the ectoplasm is filled with frothy vacuoles and lipid droplets, keeping them buoyant. Often it also contains symbiotic algae, especially zooxanthellae, which provide most of the cell's energy. Some of this organization is found among the heliozoa, but those lack central capsules and only produce simple scales and spines. Image File history File links Size of this preview: 450 × 599 pixelsFull resolution (2115 × 2814 pixel, file size: 1. ... Image File history File links Size of this preview: 450 × 599 pixelsFull resolution (2115 × 2814 pixel, file size: 1. ... The Challenger Expedition was a scientific expedition that made many discoveries to lay the foundation of oceanography. ... Pseudopods or pseudopodia (false feet) are temporary projections of eukaryotic cells. ... Microtubules are one of the components of the cytoskeleton. ... The eukaryotic cell nucleus. ... Schematic of typical animal cell, showing subcellular components. ... Schematic of typical animal cell, showing subcellular components. ... A polyunsaturated triglyceride. ... Meat Ants harvest Leaf Hoppers for their honey dew. ... Zooxanthellae are golden-brown intracellular endosymbionts of various marine animals and protozoa, especially anthozoans. ... Heliozoa, or sun animalcules, are roughly spherical amoeboids with many stiff, microtubule-supported projections called axopods radiating outward from the cell surface. ...

The main class of radiolarians are the Polycystinea, which produce siliceous skeletons. These include the majority of fossils. They also include the Acantharea, which produce skeletons of strontium sulfate. Despite some initial suggestions to the contrary, genetic studies place these two groups close together. They also include the peculiar genus Sticholonche, which lacks an internal skeleton and so is usually considered a heliozoan. Scientific classification or biological classification refers to how biologists group and categorize extinct and living species of organisms. ... The polycystines are a group of radiolarian protists. ... The chemical compound silicon dioxide, also known as silica, is the oxide of silicon, chemical formula SiO2. ... The Acantharea are a small group of radiolarian protozoa, distinguished mainly by their skeletons. ... Celestite (SrSO4) is a mineral consisting of strontium sulfate. ... Sticholonche is a peculiar genus of protozoan with a single species, , found in open oceans at depths of 100-500 metres. ...

Traditionally the radiolarians have also included the Phaeodarea, which produce siliceous skeletons but differ from the polycystines in several other respects. However, on molecular trees they branch with the Cercozoa, a group including various flagellate and amoeboid protists. The other radiolarians appear near, but outside, the Cercozoa, so the similarity is due to convergent evolution. The radiolarians and Cercozoa are included within a supergroup called the Rhizaria. The Phaeodarea are a group of amoeboid protozoa. ... The Cercozoa are a group of protists, including most amoeboids and flagellates that feed by means of filose pseudopods. ... Flagellata from Ernst Haeckels Artforms of Nature, 1904 Parasitic excavate (Giardia lamblia) Green alga (Chlamydomonas) Flagellates are cells with one or more whip-like organelles called flagella. ... Amoeba (Chaos diffluens) Foraminiferan (Ammonia tepida) Heliozoan (Actinophrys sol) Amoeboids are cells that move or feed by means of temporary projections, called pseudopods (false feet). ... Typical phyla Chromista Heterokontophyta Haptophyta Cryptophyta (cryptomonads) Alveolata Dinoflagellata Apicomplexa Ciliophora (ciliates) Excavata Euglenozoa Percolozoa Metamonada Rhizaria Radiolaria Foraminifera Cercozoa Archaeplastida (in part) Rhodophyta (red algae) Glaucophyta (basal archaeplastids) Amoebozoa Choanozoa Many others; classification varies Protists (IPA: ) are a diverse group of organisms, comprising those eukaryotes that are not animals... In evolutionary biology, convergent evolution is the process whereby organisms not closely related, independently evolve similar traits as a result of having to adapt to similar environments or ecological niches. ... The Rhizaria are a major line of protists. ...

Some radiolarians and known for their resemblance with regular polyhedra such as this icosahedron shaped one. Circogonia Icosahedra from Haeckels 1904 Kunstformen der Natur. 157 by 175 pixels, 6172 bytes. ... Possible classes Polycystinea Acantharea Taxopodea Radiolaria are amoeboid protozoa that produce intricate mineral skeletons, typically with a central capsule dividing the cell into inner and outer portions, called endoplasm and ectoplasm. ... This article is about the geometric shape. ...

Haeckel's radiolarians

German biologist Ernst Haeckel produced exquisite (and perhaps somewhat exaggerated) drawings of radiolaria, helping to popularize these protists among Victorian parlor microscopists alongside foraminifera and diatoms. Ernst Haeckel. ... Orders Allogromiida Carterinida Fusulinida - extinct Globigerinida Involutinida - extinct Lagenida Miliolida Robertinida Rotaliida Silicoloculinida Spirillinida Textulariida incertae sedis    Xenophyophorea    Reticulomyxa The Foraminifera, or forams for short, are a large group of amoeboid protists with reticulating pseudopods, fine strands that branch and merge to form a dynamic net. ... Orders Centrales Pennales Diatoms (Greek: (dia) = through + (temnein) = to cut, i. ...

Illustrations from Kunstformen der Natur (1904)

1. Phaeodaria Image File history File links Download high resolution version (2320x3284, 1595 KB) Summary The 1st plate from Ernst Haeckels Kunstformen der Natur (1904), depicting radiolarians, classified as Phaeodaria. ...	11. Discoidea Image File history File linksMetadata Download high resolution version (2304x3284, 1589 KB) Summary The 11th plate from Ernst Haeckels Kunstformen der Natur (1904), showing radiolarians classified as Discoidea. ...	21. Acanthometra Image File history File links Download high resolution version (2346x3294, 1800 KB) Summary The 21st plate from Ernst Haeckels Kunstformen der Natur (1904), depicting radiolarians classified as Acanthometra. ...	22. Spyroidea Image File history File links Download high resolution version (2286x3326, 1511 KB) Summary The 22nd plate from Ernst Haeckels Kunstformen der Natur (1904), depicting radiolarians classified as Spyroidea. ...
31. Cyrtoidea Image File history File links Download high resolution version (2309x3271, 1722 KB) Summary The 31st plate from Ernst Haeckels Kunstformen der Natur (1904), depicting radiolarians classified as Cyrtoidea. ...	41. Acanthophracta Image File history File links Download high resolution version (2332x3262, 1752 KB) Summary The 41st plate from Ernst Haeckels Kunstformen der Natur (1904), depicting radiolarians classified as Acanthophracta. ...	51. Polycyttaria Image File history File links Download high resolution version (2364x3285, 1794 KB) Summary The 51st plate from Ernst Haeckels Kunstformen der Natur (1904), depicting radiolarians classified as Polycyttaria. ...	61. Phaeodaria Image File history File links Download high resolution version (2314x3290, 1826 KB) Summary The 61st plate of Ernst Haeckels Kunstformen der Natur (1904), depicting radiolarians classified as Phaeodaria. ...
71. Stephoidea Image File history File links Download high resolution version (2320x3292, 1745 KB) Summary The 71st plate from Ernst Haeckels Kunstformen der Natur (1904), showing Radiolarians of the order Stephoidea. ...	91. Spumellaria Image File history File links Download high resolution version (2344x3324, 1631 KB) Summary The 91st plate, illustrating the Spumellaria subclass of Radiolarians, from Ernst Haeckels 1904 Kunstformen der Natur. ...

References

External links

Wikimedia Commons has media related to:

Radiolaria

• Radiolarians
• Geometry and Pattern in Nature 3: The holes in radiolarian and diatom tests
• Radiolaria.org