the large dromaeosaurids descend from small flying dinosaurs,
they share a lot of arm anatomy with animals such as Archaeopteryx.
They have long, strong arms, suitable for grasping. They can
fold these appendages tightly like a bird.
have 3 fingers, the shortest being the thumb, and the longest
being the middle finger. The thumb and the pinkie have more
mobility, the pinkie being the most flexible, but the middle
finger is not totally immobilized.
fingers lack the nimbleness of human fingers, and should not
be drawn as such. These hands also naturally sit on an angle
on the wrist, unlike human hands. A resting Raptor hand will
sit naturally with it's thumb at the front, and the palms facing
inward. The wrist configuration is what allows the hand to fold
so tightly. The lower arm is comprised of two bones, like a
human's, and so there is some degree of rotation. The arms were
built to make fast, powerful grabs at prey: moving first upwards,
and then down and forwards (much like a bird's wing stroke).
should resemble the toes of birds: being bony and scaled. The
skin should be pebbled and rough. The areas under the fingers
should be semi-padded and scaly. When fleshing out the arm,
keep in mind it's function: there is no need for articulate
movements, only grabbing. They must not look like human arms,
as they serve a different function.
above illustration shows how the feathers should come out of
the middle finger. Arms were most likely appendages used for
display. Naturally this would lend itself to sometimes drawing
long display feathers on the arms. Refrain from giving larger
species "wings," as the big Raptors did not evolve
for gliding, and thus would not have feather orientation like
birds (no primaries, or complex layering). The proto feathers
would probably be bristly at the tops, with the long display
feathers towards the bottom. Just how they look is up to your
imagination, go nuts, but remember that they must be functional.
It would not do well to have flopping feathers in the way while
trying to bring down a hadrosaur.