Monday, November 7, 2011



"The pterosaur wing membrane is divided into three basic units. The first, called the propatagium ("first membrane"), was the forward-most part of the wing and attached between the wrist and shoulder, creating the "leading edge" during flight."


"Here is an image of a White Ibis in flight showing full breeding plumage, in this instance the bird is pushing it's wings down and the arm is stretched out. As you can see, we get a good view of where the bones are positioned in the wing, notice that they don't run along the front of the wing. The elbow is set back from the leading edge and the bend in the arm is hidden by the Propatagium, a fold of skin inside the front part of the wing which connects to the shoulder and the wrist."
"The [bird] propatagium is variably deployed, relative to elbow extension, in flight; support for its cambered shape is maintained by multilayered collagenous and elastic tissue networks suspended between leading edge and dorsal antebrachium." 

1 comment:

  1. Here are a couple of articles on the bird propatagium:;2-R/abstract
    Through flight experiments with live birds and computer modeling we define the aerodynamic contributions of the propatagium in avian flight. From flight trials we found that in House Sparrows, with all flight feathers removed except for the distal six primaries, the loss of approximately 50% of the propatagium's projected area and its cambered profile produced a significant reduction in the distance a bird was able to cover in flight.
    The supporting elements of the avian propatagium were examined in intact birds and as isolated components, using static force-length measurements, calculated models, and airflow observations. The propatagial surface supported between Lig. propatagiale (LP) and brachium-antebrachium is equally resistant to distortion over the range of wing extension used in flight.