rigifilida rigifilida rigifilida is a clade of non-ciliate phagotrophic eukaryotes. it consists of two genera: micronuclearia and rigifila. rigifilida scientific classification domain: eukaryota clade: opimoda clade: crums order: rigifilidacavalier-smith 2012 family micronucleariidae rigifilidae characteristics cells of rigifilids are covered with either a single or a double-layered submembrane pellicular lamina that makes them rigid in consistence. slender branching filopodia emanate from a ventral aperture of the cell and are employed to collect bacteria upon which they feed and to attach the organism to the substratum. around this aperture, the pellicle is reflexed around forming a peristomial collar. other notable features are flat and irregular shaped mitocondrial cristae, a single dorsal nucleus and the lack of centrioles and cilia. phylogeny scotokaryota metamonada cavalier-smith 1987 emend. cavalier-smith 2003 opimoda ancyromonadida cavalier-smith 1998 emend. atkins 2000 malawimonadea cavalier-smith 2003 amorphea amoebozoa lühe 1913 emend. cavalier-smith 1998 obazoa breviatea cavalier-smith 2004 apusomonadida karpov & mylnikov 1989 opisthokonta crums mantamonadida cavalier-smith 2004 rigifilida karpov & mylnikov 1989 diphylleida cavalier-smith 1993 taxonomy rigifilida is currently placed in crums. order rigifilida cavalier-smith 2012 family rigifilidae yabuki & cavalier-smith 2012 genus rigifila yabuki & cavalier-smith 2012 species rigifila ramosa yabuki & cavalier-smith 2012 family micronucleariidae cavalier-smith 2008 genus micronuclearia mikrjukov & mylnikov 2001 species micronuclearia podoventralis mikrjukov & mylnikov 2001