Re: four winged Archaeopteryx

[GSP1954@aol.com]

The humerus has a greater diameter than the femur, and the radius and ulna 
are more robust than the tibia and fibula. If the arms of Archaeopteryx were 
for 
display or turning etc while running then the arms should not have been as 
strongly built as the running legs. That the opposite is true indicates the 
arms 
bore the primary load in some form of locomotion. Climbing is a partial 
explanation, but only in flight would the arms bear almost or all of the load. 
Add 
the enormous wings (same wingarea & span/mass ratios as in standard birds), 
very large arm muscles much bigger than in normal theropods, and so forth and 
you have something that is beyond passive gliding and into some crude form of 
powered flight. As for the tail feathers well peacocks fly. 

When I manipulated the humerus of Coelophysis rhodesensis in the laterally 
facing glenoid of a cast many years ago I had no trouble getting it to go way 
above horizontal, diagram in PDW; same with Deinonychus (this is not doable in 
all theropods). In Archaeopteryx the glenoid faces at least as laterally. 

GSPaul