Re: Paedomorphosis ( Re: BARYONYX' CLAWS )

[Dinogeorge <Dinogeorge@aol.com>]

In a message dated 98-04-11 13:51:14 EDT, m_troutman@hotmail.com writes:

<< Now, if 
 in theropods, they needed to use their forelimbs for predation : why 
 wouldn't they lose flight the typical avian way ( paedomorphosis ) and 
 tweak their forelimbs to work the way it does in phorusrhacids ? ( in 
 which flight was lost the typical avian way and the forelimbs was 
 modified ). >>

Perhaps they did it in just this way. But theropods were not typical avians,
because at the time theropods began to appear, typical avians were still well
in the future. So all bets are off as to the details of the mechanism whereby
they became flightless, ground-dwelling forms. Not having evolved all the gear
that birds have for powered flying doubtless gave theropods considerably more
leeway in the mechanisms available to them for becoming secondarily
flightless. By the time you're a full-fledged bird, the quickest route to
flightlessness can only be paedomorphosis.