connected to connected to manus remex feather primary remex feather primary remex primary remiges these are the longest and narrowest of the remiges (particularly those attached to the phalanges), and they can be individually rotated. These feathers are especially important for flapping flight, as they are the principal source of thrust, moving the bird forward through the air. Most thrust is generated on the downstroke of flapping flight. However, on the upstroke (when the bird often draws its wing in close to its body), the primaries are separated and rotated, reducing air resistance while still helping to provide some thrust Wikipedia:Flight_feather#Primaries primary flight feather UBERON:0011796 A remex feather that is connected to the manus.