How creationism explains the Archaeopteryx

Sorry. This is incorrect. While it cannot be determined if there were or were not air sacs as in modern birds, the bones of Archaeopteryx were hollow. I refer you to "Taking Wing" by Pat Shipman.

The more complete reference:Pat Shipman. 1998. Taking Wing: Archaeopteryx and the Evolution of Bird Flight. Touchstone. New York. 336 p.There is also:Gregory S. Paul. 2002. Dinosaurs Of The Air: The Evolution and Loss of Flight in Dinosaurs and Birds. The Johns Hopkins University Press, Baltimore. 460 p.While the latter book present a quite different view of the origin of bird flight, is still makes it clear that Archaeopteryx had hollow, possibly pneumatic, bones.