GSP's article in PT#60 and discussions on message boards made me examine more carefully the photos of _Sinornithosaurus_ sp. aka "Dave". Is that evidence of a hinwing that I see below a foot on the counterslab? So was "Dave" 4-winged? http://research.amnh.org/vertpaleo/feather2.jpg Many thanks in advance for any thoughts. Cheers - Aspidel.