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Re: Fw: Theropods/pterosaurs -- pollinators?



HP Jim Cunnungham wrote:

Please describe to me the technique that Quetzalcoatlus northropi uses while landing on a flexible cycad or palm branch.

reply: <I didn`t mean to imply that all pterosaurs landed on cycad branches,...only the smaller variety.> 

Hummingbirds don't open their feathers on the 'upstroke' when they hover.  This is also true of other birds when using the 'momentum reversal' technique for hovering.  And it's quite possible that some small pterosaurs could hover for short periods using camber inversion on the 'upstroke', but I haven't attempted to calculate the hovering beat kinematics for small pterosaurs, so that's just speculation on my part. 
<Camber inversion? Do you think it was possible?>
 
 Also as an aside, Quetzalcoatlus species, with a head/neck length of about 8.2 feet and a length from notarium socket to acetabulum of about 12.25 inches, doesn't appear to have been 'top heavy'.  Perhaps I'm missing something here? 
<by "top heavy", I`m referring to everything above the balance point of the hip joint> I think that all pterosaurs must have come down pretty hard on their forepaws when landing.>
<PS...I`m still looking into exactly what birds do when they land. I don`t think they all hover either. Just been observing bluejays landing at the feeder. They do seem to go into a stall just before landing.Can`t see it up close, but the alula must play a significant role.Also the ability to absorb the shock with the leg muscles. It is not a simple process, but I still can`t see how pterosaurs could have accomplished a foot only contact landing in a relatively stiff perch (despite the pterodactyls in JPIII !).
pps Sad news to here about S. J. Gould passing away. (was going to write him about some of my ideas,...guess I waited too long).