The tectofilosids are a group of filose

amoeba An amoeba (; less commonly spelled ameba or amœba; plural ''am(o)ebas'' or ''am(o)ebae'' ), often called an amoeboid, is a type of Cell (biology), cell or unicellular organism with the ability to alter its shape, primarily by extending and ret ...

e with shells. These are composed of organic materials and sometimes collected debris, in contrast to the

euglyphid The euglyphids are a prominent group of filose amoebae that produce shells or tests from siliceous scales, plates, and sometimes spines. These elements are created within the cell and then assembled on its surface in a more or less regular arra ...

s, which produce shells from siliceous scales. The shell usually has a single opening, but in '' Amphitrema'' and a few other genera it has two on opposite ends. The cell itself occupies most of the shell. They are most often found on marsh plants such as ''

Sphagnum ''Sphagnum'' is a genus of approximately 380 accepted species of mosses, commonly known as sphagnum moss, peat moss, also bog moss and quacker moss (although that term is also sometimes used for peat). Accumulations of ''Sphagnum'' can store wa ...

''. This group was previously classified as the Gromiida or Gromiina. However, molecular studies separate ''

Gromia ''Gromia'' is a genus of protists, closely related to foraminifera, which inhabit marine and freshwater environments. It is the only genus of the family Gromiidae. ''Gromia'' are ameboid, producing filose pseudopodia that extend out from the cel ...

'' from the others, which must therefore be renamed. They are placed among the

Cercozoa Cercozoa is a phylum of diverse single-celled eukaryotes. They lack shared morphological characteristics at the microscopic level, and are instead defined by molecular phylogenies of rRNA and actin or polyubiquitin. They were the first major eu ...

, and presumably developed from

flagellate A flagellate is a cell or organism with one or more whip-like appendages called flagella. The word ''flagellate'' also describes a particular construction (or level of organization) characteristic of many prokaryotes and eukaryotes and their ...

s like ''

Cryothecomonas Cryomonadida is a group of heterotrophy, heterotrophic Rhizaria, that belong to the Cercozoa. Characteristics Members of the Cryomonadida are single-celled organisms that are surrounded by a shell comprising layers of organic material. They poss ...

'', which has a similar test. However, only a few have been studied in detail, so their relationships and

monophyly In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic grou ...

are not yet certain. In a recent classification, the group Tectofilosida was not used: Chlamydophryidae, Psammonobiotidae,

Pseudodifflugiidae ''Pseudodifflugia'' is a genus of Cercozoa Cercozoa is a phylum of diverse single-celled eukaryotes. They lack shared morphological characteristics at the microscopic level, and are instead defined by molecular phylogenies of rRNA and actin or ...

and Volutellidae were dispersally placed in

Thecofilosea Thecofilosea is a class of Cercozoa. References Cercozoa classes {{Cercozoa-stub ...

, while Amphitremidae was included in

Labyrinthulomycetes The Labyrinthulomycetes (ICBN) or Labyrinthulea (ICZN) are a class of protists that produce a network of filaments or tubes, which serve as tracks for the cells to glide along and absorb nutrients for them. The two main groups are the labyrint ...

Taxonomy

* Order

Tectofilosida The tectofilosids are a group of filose amoebae with shells. These are composed of organic materials and sometimes collected debris, in contrast to the euglyphids, which produce shells from siliceous scales. The shell usually has a single open ...

Cavalier-Smith & Chao 2003 (paraphyletic) ** Suborder Lithocollina Cavalier-Smith 2012 *** Family Lithocollidae Schulze 1874 ** Suborder Unitremina Cavalier-Smith 2012 *** Family Rhizaspididae Howe et al. 2011 hizaspidaceae Skuja 1948*** Family Fiscullidae Dumack et al. 2017 *** Family

De Saedeleer 1934 *** Family Psammonobiotidae Golemansky 1974 emend Meisterfeld 2002 *** Family Chlamydophryidae de Saedeleer 1934 emend. Meisterfeld 2002 *** Family Volutellidae Sudzuki 1979

References

{{Taxonbar, from=Q7692831 Filosa Amoeboids