re: Dodos, Swifts and Quetzalcoatlus.

[David Peters <davidrpeters@earthlink.net>]

Michael Lovejoy wrote:

I don't know much about pterosaurs, but while looking at bird skeletons
in
DA, page 146, I noticed that the albatross has the long thin humerus
that
I'd expect in a soarer, but Quetzalcoatlus has a humerus very similar to
a
swift! Anybody know why? Were they agile fliers, or is it for a powerful

take-off, or what?

>>>>
Not sure about the swift humerus shape, but perhaps you're
unintentionally commenting on the relative length of the humerus in the
albatross and  Q.

Whether hanging on trees or wading in shallows, pterosaurs were
quadrupedal, unlike birds, so the forelimb minus the folding wing finger
has to more or less equal the hindlimb minus the pes. It's something of
a constraint on their engineering, I suppose, to keep the proximal
elements related in size. In the exceptional pteros, such as
Nyctosaurus, Pteranodon and some ornithocheirids, where the proximal
forelimb elements greatly exceed the hindlimb elements, then elbow
bending effectively reduces the forelimb length, or, as Chris Bennett
has shown, the pterosaur simply lifts its oversized forelimbs up and
walks bipedally.

Now the swift is another story...

Hope this helps.

David Peters
St. Louis