"Monothalamea" traditionally contains two groups, neither of which is currently considered to be
monophyletic: • "
Allogromiida" traditionally consists of all foraminifera which lack a mineralised test, instead having a test of tectin. Recent work has shown that this grouping is
paraphyletic. • "
Astrorhizida" traditionally consists of all foraminifera with single-chambered, agglutinated tests. Recent work has shown that this grouping is
polyphyletic, as agglutinated tests have evolved from proteinaceous tests multiple times throughout foraminiferal evolution. Molecular evidence has also revealed that the freshwater
protist Reticulomyxa is in fact a naked, testless foraminifera, and as such it has been included with monothalameans in scientific discussion. A 2013 molecular study using
small subunit rDNA concluded that known monothalameans made up at least 22 distinct living clades from marine environments with an additional four clades from freshwater
eDNA. == References ==