Sphenoderiidae (fam. nov.), a New Clade of Euglyphid Testate Amoebae Characterized by Small, Round Scales Surrounding the Aperture

Euglyphid testate amoebae are a highly conspicuous group of Cercozoa whose systematics is based mainly on the shape and ultrastructure of the shell. However, only a couple of species have been studied with molecular methods. As a consequence, there are still some genera whose classification remains uncertain. Amongst those are <i>Sphenoderia</i> and <i>Trachelocorythion</i>, two genera with diverging ecological requirements that share a collar composed of small scales around the aperture. We demonstrate here with a molecular and morphological approach that they are closely related, and propose a new family, Sphenoderiidae fam. nov. to group these species. Some species share almost similar morphology in spite of being genetically distantly related (<i>Sphenoderia minuta</i> and <i>S. pseudominuta</i> sp. nov.), underlining the importance of combining ultrastructural and morphological data when describing new species of protists. In addition, we describe here <i>Sphenoderia valdiviana</i> sp. nov., a new species isolated from Southern Chile temperate rainforests.