Sirens

During the events of Resistance: Retribution, the Furies are referenced as Sirens. It is unknown if these are actually Furies or a completely other Chimera strain, but given that the Resistance 2 Furies cannot fire telekinetic blasts as they can in Resistance: Retribution. This may mean that Sirens and Furies are two similar, but different strains. Similar to how brutes are similar to the Ravager. So this could mean th sirens are direct predecessor to the Furies