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

Re: Last of the Pterosaurs



Daniel Bensen wrote:
 
<Isn't the current theory that Cretaceous pterosaurs were so large
because birds pushed them out of all the small-flier niches?>

  Correct me if I'm wrong, but I don't believe this hypothesis has been
tested, or put in print ... it is plausible, but one has to do a
diversity test where one has birds and pterosaurs in the same level
across the globe or at several reasonable localities and can quantifiy
relative levels. Then scale mass or biomass to the data, and test the
results with more data ...

McDevitt wrote:

<<Quetzalcoatlus was so big that it could not have taken off without
help from the winds whistling through the mountains and canyons of
Texas, USA. Once in the air, it could glide on the air currents for a
long time.>>

<I doubt that any animal could survive if its mobility was so utterly
dependent on something as capricious as wind. Who was that who did a
study of pterosaur anatomy and how those animals could have lifted off?
Didn't they use Quetzalcoatlus for that study?>

  The study has not been published. It was slated to be presented at
SVP in Denver last year, but that fell through and we got Ruben's
*Longisquama* presentation instead. Jim Cunningham may have something
to say on this, as it's his and Langston's project, but so far ... Tom
Holtz reply #1.

  Besides, how big is big? I also don't know if Quetz' mass has been
calculated [Art Andersen is working on mass in pterosaurs, in relation
to locomotion on the ground, but if he's done an estimate for Quetz sp.
or Q. northropi, I'm unaware of it]. For a skull ~2m long, it's flat at
the tip, and very thin from front to back, same for the neck, body (you
could probably carry the creature -- Q. sp, anyway), and limbs, which
were _very_ light and hollow.

=====
Jaime "James" A. Headden

  Dinosaurs are horrible, terrible creatures! Even the
  fluffy ones, the snuggle-up-at-night-with ones. You think
  they're fun and sweet, but watch out for that stray tail
  spike! Down, gaston, down, boy! No, not on top of Momma!

__________________________________________________
Do You Yahoo!?
Yahoo! Shopping - Thousands of Stores. Millions of Products.
http://shopping.yahoo.com/