Spumellaria is an order of

radiolarian The Radiolaria, also called Radiozoa, are protozoa of diameter 0.1–0.2 mm that produce intricate mineral skeletons, typically with a central capsule dividing the cell into the inner and outer portions of endoplasm and ectoplasm. The elab ...

s in the class Polycystinea. They are ameboid

protists A protist () is any eukaryotic organism (that is, an organism whose cells contain a cell nucleus) that is not an animal, plant, or fungus. While it is likely that protists share a common ancestor (the last eukaryotic common ancestor), the excl ...

appearing in abundance in the world's oceans, possessing a radially-symmetrical silica (opal) skeleton that has ensured their preservation in fossil records. They belong among the oldest Polycystine organisms, dating back to the lower

Cambrian The Cambrian Period ( ; sometimes symbolized C with bar, Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million ...

(ca. 515 million years). Historically, many concentric radiolarians have been included in the ''Spumellaria'' order based on the absence of the initial spicular system, an early-develop structure that, by its lacking, sets them apart from '' Entactinaria'' despite their similar morphology.
Mendez Sandin. Diversity and Evolution of Nassellaria and Spumellaria (Radiolaria). Protistology. Sorbonne Université, 2019. English. Accessed at: https://tel.archives-ouvertes.fr/tel-03137926/file/MENDEZ_SANDIN_Miguel_2019.pdf on 2022-10-18 Living exemplars of the order feed by catching prey, such as

copepod Copepods (; meaning "oar-feet") are a group of small crustaceans found in nearly every freshwater and saltwater habitat (ecology), habitat. Some species are planktonic (inhabiting sea waters), some are benthos, benthic (living on the ocean floor) ...

nauplii Nauplius, Nauplia or Nauplios , may refer to : Greece-related * Nauplius (mythology), in Greek mythology, the son of Poseidon and Amymone, the father of Palamedes, and also the name of an Argonaut * Nauplia Nafplio ( ell, Ναύπλιο) is a ...

tintinnids Tintinnids are ciliates of the choreotrich Order (biology), order Tintinnida, distinguished by vase-shaped shells, the name deriving from a Latin source meaning a small tinkling bell, that are called'' Lorica (biology), loricae'', which are mostl ...

, on the adhesive ends of their

pseudopodia A pseudopod or pseudopodium (plural: pseudopods or pseudopodia) is a temporary arm-like projection of a eukaryotic cell membrane that is emerged in the direction of movement. Filled with cytoplasm, pseudopodia primarily consist of actin filament ...

extending radially from their skeleton; however, some have been observed as

mixotrophs A mixotroph is an organism that can use a mix of different sources of energy and carbon, instead of having a single trophic mode on the continuum from complete autotrophy at one end to heterotrophy at the other. It is estimated that mixotrophs comp ...

living in symbiosis with various photosynthetic algal organisms such as

dinoflagellates The dinoflagellates (Greek δῖνος ''dinos'' "whirling" and Latin ''flagellum'' "whip, scourge") are a monophyletic group of single-celled eukaryotes constituting the phylum Dinoflagellata and are usually considered algae. Dinoflagellates are ...

cyanobacteria Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blu ...

prasinophytes The prasinophytes are a group of unicellular green algae. Prasinophytes mainly include marine planktonic species, as well as some freshwater representatives.Sym, S. D. and Pienaar, R. N. 1993. The class Prasinophyceae. In Round, F. E. and Chapma ...

haptophytes The haptophytes, classified either as the Haptophyta, Haptophytina or Prymnesiophyta (named for '' Prymnesium''), are a clade of algae. The names Haptophyceae or Prymnesiophyceae are sometimes used instead. This ending implies classification at ...

, which may cause their distribution to center in the greatest abundance and diversity within trophical waters.

Families

* Actinommidae * Anakrusidae * Angulobracchiidae * Archaeospongoprunidae * Astrosphaeridae * Bolenidae *

Catenopylidae Catenopylidae is a family of radiolarians in the order Spumellaria Spumellaria is an order of radiolarians in the class Polycystinea. They are ameboid protists appearing in abundance in the world's oceans, possessing a radially-symmetrical si ...

* Cavaspongiidae * Coccodiscidae * Conocaryommidae * Dactyliosphaeridae * Emiluviidae * Entapiidae * Ethmosphaeridae * Gomberellidae * Hagiastridae * Heliodiscidae * Hexaporobrachiidae * Larnacillidae * Leugeonidae * Litheliidae * Miropylidae * Myelastridae * Oertlispongidae * Orbiculiformidae * Pantanelliidae * Parasaturnalidae * Parvivaccidae * Patulibracchiidae * Patruliidae * Phacodiscidae * Phaseliformidae * Praeconocaryommidae * Pseudoacanthocircidae * Pseudoaulophacidae * Pyloniidae * Pyramispongiidae * Relindellidae * Spongodiscidae * Sponguridae * Stylosphaeridae * Thalassicollidae * Tholoniidae * Tritrabidae * Veghicycliidae * Xiphostylidae In addition, several

taxa In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular nam ...

in this order are still considered ''incertae sedis''.

Gallery

File:Haeckel Spumellaria detail.png, ''Hexancistra quadricuspis'' shell (

Haeckel Ernst Heinrich Philipp August Haeckel (; 16 February 1834 – 9 August 1919) was a German zoologist, naturalist, eugenicist, philosopher, physician, professor, marine biologist and artist. He discovered, described and named thousands of new sp ...

) File:Haeckel Spumellaria.jpg, Shells of (mostly) Spumellaria (Haeckel) File:Radiolaria (Challenger) Plate 014.jpg, Spumellaria from the

Challenger Expedition The ''Challenger'' expedition of 1872–1876 was a scientific program that made many discoveries to lay the foundation of oceanography. The expedition was named after the naval vessel that undertook the trip, . The expedition, initiated by Wil ...

References

External links

Polycystines Retaria orders {{Radiolarian-stub