Class Tubothalamea Pawlowski, Holzmann & Tyszka 2013
Diagnosis: Bi- or multi-chambered test with tubular chambers at least in the juvenile stage; wall agglutinated or calcareous; in ancestral forms the test is composed of a spherical proloculus followed by a spirally enrolled tubular chamber; more evolved forms have multi-chambered tests;
Molecular characteristics: relatively short SSU rRNA gene (2289–2866 nt) and very low GC content (< 30%).
Stratigraphic range: Lower Cambrian – Recent.
- Order Miliolida (Delage and Hérouard, 1896) emend
Test bi- or multi-chambered, chambers tubular or elongate, some with complex internal structures adapted to host algal endosymbionts; wall generally imperforate, calcareous of high magnesium calcite with randomly oriented crystals refracting light in all directions and resulting in a porcelaneous appearance of the test; may be agglutinated or siliceous in some taxa (Miliammina, Miliammellus).
- Order Spirillinida (Hohenegger and Piller, 1975) emend
Test composed of proloculus followed by an enrolled tubular chamber, aperture terminal; wall of low magnesium calcite, optically a single crystal in Spirillinidae and Patellinidae; wall agglutinated in Ammodiscidae.
Source: Pawlowski J., Holzmann M., Tyszka J., 2013. New supraordinal classification of Foraminifera: Molecules meet morphology. Marine Micropaleontology, available online 17 April 2013, http://dx.doi.org/10.1016/j.marmicro.2013.04.002