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Re: Protoavis



OK, let`s clear some things up (maybe)...

Jaime wrote:

>-----Original Message-----
>From: Jaime A. Headden <qilongia@yahoo.com>
>To: dinosaur@usc.edu <dinosaur@usc.edu>
>Cc: ptnorton@email.msn.com <ptnorton@email.msn.com>; larryf@capital.net
<larryf@capital.net>; >dinogeorge@aol.com <dinogeorge@aol.com>
>Date: Monday, March 01, 1999 12:57 AM
>Subject: Re: Protoavis


>Patrick Norton wrote:
>
><why would a theropod have such an advanced flight related structure>

(No,...Larry Febo.,.aka I, Me Myself,...wrote that!)




>
>and Larry Febo wrote:
(Substitute Pat Norton)

><<I believe there are Coelurosaurs outside of Avialae that possess an
>acrocoracoid tuberosity, so I'm not sure it is necessarily a flight
>related feature.>>



(Jamie wrote:)
>
>  In the concepts of BCF and 2ndF'lessness, such a feature would be
>tell-tale signs of a common, early origin of flight. Or in BAMMness,
>it would be a sign of a development for something that was exapted
>into a flight structure. Doesn't mean "flight"; pterosaurs and bats
>lack such a feature and fly pretty darn well, as I'm sure Matt and
>other bird-types will say.

Larry says:
Pterosaurs did have (what is termed by Padian at least) an acrocoracoid
process. They may have lacked the furcula as part of the structure, but it`s
there nonetheless, and functions pretty much exactly as it does for a bird.
As far as bats flying as "good" as birds,...it`s pretty subjective, but I
don`t think they`re as good long range, and I`m assuming that hummingbirds
might be able to outmaneuver them...(though not at night!).Archie flew , I
think,..(although some say not very efficiently),...it did not have an
acrocoracoid process,...did have a biceps tubercle though.



>
>and Pat Norton replied:
><Just to follow up (I just found the article I was thinking about)
>Gauthier (1986) found a pronounced coracoid tuberosity among the
>Deinonychosauria as well as Avialae.>
>
>  It argues a well-supported clade between troodontids and
>bird-related theropods, because oviraptors also have an acrocoracoid
>process/tuberosity, and their scapulocoracoids are virtually identical
>to dromaeosaurids. It seems to support a clade where troodontids are
>the closest outgroup to the Oviraptorosauria + (Dromaeosauridae +
>Avialae) clade. Wait 'til we find furculae in troodontids. Given
>Mongolia's excellent preservation, that shouldn't be long if they're
>there, but troodontids have always been fragmentary finds, and no,
>*Saurornithoides* does not preserve a furcula: what's there are two
>"clavicle"-like fragments on each side of the pectoral girdle, as in
>*Segisaurus*, and may represent an ill-ossified furcula.
>
>  Have fun,
>
>==
>- Often, it is the man who is brought
>  down the path to the end who does
>  not see his own steps. -
>
>Jaime A. Headden
>
>Qilong, the website, at:
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