[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: Sinocalliopteryx (Theropoda: Compsognathidae) ate confuciusornithids and dromaeosaurids
I think it is understating the case to say that all you need is an airfoil. Ok,
yes, seeds do that, if all you want to do is avoid plummeting straight down,
but if you want to control the direction, elevation etc of the glide you have
to be able to control aspects of the gliding surface. What would be the
anatomical features you would need to do this in a bird-type wing without
actually flying (and I don't mean soaring or sailplaning like a condor or an
albatross - I accept that Archie couldn't do that!).
Sent from my iPad
On Sep 4, 2012, at 10:27 PM, GSP1954@aol.com wrote:
> I went on and on about this in a book I published back in 1988, and another
> n 2002, and a reply to a notoriously defective Science paper in 2010. To
> lide merely requires the ability to spread out an airfoil. Archeopteryx and
> inornithosaurs and all basal birds with large wings had way too many
> dditional flight adaptations to merely glide, they were powered fliers of
> ort or another using a basal system for flapping their arm wings. Quite
> ossibly not very well, but we might be surprised what they could do.
> Having seen the Archaeopteryx shoulder glenoids and those of many theropods
> and flying birds it is very unlikely that the basal fliers could elevate
> the humerus to vertical the way birds can (I sometimes show the arm
> elevated in basal flier skeletals just to show the wing profile). Extremely
> unlikely they could take off vertically, but with a jumping-running start
> may have been able to take off from the ground. Or maybe not.
> n a message dated 9/1/12 12:12:15 PM, email@example.com writes:
> << Man I so agree with you and Dr. Holtz. Right on.
> That was one of my first thoughts, when I started my first Microraptor
> econstruction 8 years ago. I thought "well, flight in modern birds, with a
> ully derived pectoral anatomy, is superlative. Arctic terns fly from the
> ole to the south pole and back again every year. But what if powered
> tarted with a much more primitive pectoral anatomy that could only achieve
> ursts of flight? Maybe it completely exhausted the animal just to flap 4
> eters over a stream or into a thicket, but that was enough." later I found
> ut that's how the modern Kagu flies.
> In other words I would not assume that a modern pectoral architecture is a
> inimum for flight, but rather a pinnacle of efficiency and performance. >>