[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Velociraptor profiles and a little background



David Marjanovic wrote:

> Hm. It is easy to imagine parachuting evolving from
> pouncing, but I can't
> imagine the flight stroke evolving that way.

Well, chances are these things didn't parachute/glide
directly on top of their prey. Some course adjustment
would be needed during the drop. So, they would be
parachuting at angles (like paragliding). If prey saw
them coming and bolted for cover there would be a need
to retain some altitude for the chase. Or if they were
going a bit too fast they would need to slow
themselves....so there are 2 examples of how the
behaviour of flapping might arise. Depending on the
height of the tree, angle of descent, and several
other factors, there would be a set area in which prey
could be caught in. Any prey that made it outside of
this circle had a pretty good chance of escaping, or
would have to be pursued on foot - *unless* you
flapped a couple times and added a few meters to this
circle. Simply angling the arm and pushing away from
the ground would give a little thrust I would think.
We might be able to obtain more information by
watching modern birds re-enact this scenario. I've
seen it before many times....next time I'll pay more
attention to exactly what they are doing.    

Cheers,
Waylon Rowley 



__________________________________________________
Do You Yahoo!?
Yahoo! Sports - live college hoops coverage
http://sports.yahoo.com/