Spumellaria is an order of
radiolarians in the class
Polycystinea. They are ameboid
protists
A protist ( ) or protoctist is any Eukaryote, eukaryotic organism that is not an animal, Embryophyte, land plant, or fungus. Protists do not form a Clade, natural group, or clade, but are a Paraphyly, paraphyletic grouping of all descendants o ...
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 ( ) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordov ...
(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 (living in the water column), some are benthos, benthic (living on the sedimen ...
nauplii or
tintinnids, on the adhesive ends of their
pseudopodia extending radially from their skeleton; however, some have been observed as
mixotrophs
A mixotroph is an organism that uses a mix of different Primary nutritional groups, sources of energy and carbon, instead of having a single trophic mode, on the continuum from complete autotrophy to complete heterotrophy. It is estimated that mixo ...
living in symbiosis with various photosynthetic algal organisms such as
dinoflagellates,
cyanobacteria
Cyanobacteria ( ) are a group of autotrophic gram-negative bacteria that can obtain biological energy via oxygenic photosynthesis. The name "cyanobacteria" () refers to their bluish green (cyan) color, which forms the basis of cyanobacteri ...
,
prasinophytes or
haptophytes, which may cause their distribution to center in the greatest abundance and diversity within trophical waters.
Families
*
Actinommidae
*
Anakrusidae
*
Angulobracchiidae
*
Archaeospongoprunidae
*
Astrosphaeridae
*
Bolenidae
*
Catenopylidae
*
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''; : 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 name and ...
in this order are still considered ''incertae sedis''.
Gallery
File:Haeckel Spumellaria detail.png, ''Hexancistra quadricuspis'' shell ( Haeckel)
File:Haeckel Spumellaria.jpg, Shells of (mostly) Spumellaria (Haeckel)
File:Radiolaria (Challenger) Plate 014.jpg, Spumellaria from the Challenger Expedition
References
External links
Radiolarian orders
Taxa named by Christian Gottfried Ehrenberg
{{Radiolarian-stub