A combine harvester (10) comprises threshing apparatus (17), a separating system (18) and a grain cleaning system (19). The threshing apparatus and separating system are arranged in series to sequentially receive and process a cut crop stream. Grain separated from the crop stream falls through respective concave grates (27, 32, 33, 44, 45, 46) in the threshing apparatus and separating system. The separating system (18) comprises a plurality of transverse separating rotors (41, 42, 43) which rotate in the same direction as one another. Each separating rotor comprises a plurality of retractable fingers (70) which retract into the rotor when at the top of the rotor and extend radially outward when at the bottom of the rotor so as to convey the crop stream under the rotors and eject crop residue from the rear of the separating system.
