A new family of entodiniomorph protozoa from the marsupial forestomach, with descriptions of a new genus and five new species.

A unique group of entodiniomorph protozoa was found in forestomach contents from quokka (Setonix brachyurus), western grey kangaroo (Macropus fuliginosus), red kangaroo (Macropus rufus) and euro (Macropus robustus erubescens). A new genus, Macropodinium n.g., containing five new species, is described. Three species are described from forestomach contents of the quokka: Macropodinium baldense n. sp., Macropodinium moiri n. sp. and Macropodinium setonixum n. sp. A single species, Macropodinium ennuensis n. sp., is described from the red kangaroo and euro. The last species, Macropodinium yalanbense n. sp., is described in forestomach contents from the western grey kangaroo. At least three distinct features in the new genus are incompatible with any of the described families in the order Entodiniomorphida. On this basis, the new family Macropodiniidae has been created.