Re: Air sacs in extant non-avian reptiles?

[chris brochu <cbrochu@fmnh.org>]

>In a message dated 7/31/00 5:46:12 PM, bettyc@flyinggoat.com writes:
>
><< In addition to 'most' paleontologists, 'most' ornthologists agree that
>there is a very strong arguement for the origin for birds having arisen
>from dinosaurs. >>
>
>Okay, can you tell me ONE professional ornthologist who belives that birds
>are currently reptiles? Not aknowleging the possibility of dinosaur ancestry,
>but currently having the same characteristics as lizards, snakes and turtles.
>


Again, you are asking for something self-contradictory.  "Birds are
reptiles" can mean two very different things:

1.  Birds are descended from the last common ancestor of turtles,
lepidosaurs, and crocodylians.  As far as I know, all professional
ornithologists accept this.

2.  Birds are scaly, sprawling, cold-blooded dimwits that hide under
creosote bushes in the desert sun.  This seems to be your definition of
"reptile," and of course no modern ornithologist would believe this - but
neither would any modern herpetologist.


Furthermore, when you look very closely at living nonavian reptiles, there
aren't that many characteristics that really bind them together
exclusively.



chris

----------------------
Christopher A. Brochu
Department of Geology
Field Museum of Natural History
1400 S. Lake Shore Drive
Chicago, IL 60605

voice: 312-665-7633
fax: 312-665-7641
electronic:  cbrochu@fmppr.fmnh.org

http://www.geology.uiowa.edu/faculty/brochu/