The amoeboid protist Ministeria vibrans occupies a key position to understand animal origins. It is a member of the Filasterea, that is the sister-group to Choanoflagellatea and Metazoa (Torruella et al.2012 and 2015). Two Ministeria amoebae species have been reported so far (Tong, 1997), both of them from coastal marine water samples: M. vibrans and M. marisola (Patterson et al. 1993). However, there is currently only one culture available, that of Ministeria vibrans.
M. vibrans is a bacterivorous amoeba with filopodia that was originally described to be suspended by a flagellum-like stalk attached to the substrate. Molecular and experimental work later on demonstrated the stalk is indeed a flagellar apparatus (Torruella et al. 2015).