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 ...
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 Skuja 1948">hizaspidaceae Skuja 1948*** Family
Fiscullidae Dumack et al. 2017
*** Family
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 ...
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