A combine harvester including a grain pan arranged to catch a crop stream. The grain pan is driven in an oscillating manner to convey the crop stream rearwardly to a rear edge from where the crop stream falls into a grain cleaning unit. A fan generates a cleaning airstream which is directed under the rear edge. The grain pan includes a conveyance floor with a rippled floor profile. A plurality of tines are provided and secured at one end to the conveyance floor. Each tine has a saw-toothed profile to lift lighter material within the crop stream away from the heavier material and enhance stratification thereof.
