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

RE: Dinosaur Revolution Review





----------------------------------------
> Date: Fri, 16 Sep 2011 12:12:25 +0200
> From: david.marjanovic@gmx.at
> To: dinosaur@usc.edu
> Subject: Re: Dinosaur Revolution Review
>
> Am 16.09.2011 05:45, schrieb Anthony Docimo:
>
> > > While the lack of scale plasticity in extant birds may very well be
> > > a derived trait, I still can't help but wonder about the old "party
> > > line" regarding why scales were lost in the first place (i.e. the
> > > weight reduction hypothesis). With the exception of osteoderms,
> > > scales are not that heavy.
 
>>> Birds get away with flying around with
> > > all kinds of strange display structures that would weigh more than
> > > a light covering of scales would.
> >
> > Some might argue that that is what birds can afford to do, after they
> > first got good at flying around.
> >
> > You can put carpets and chairs in modern planes (even small ones),
> > but the Wright Flier had to watch how much material it took on
> > board.
>
> But birds didn't lose their teeth when they started to fly. They lost
> them later, and several times independently.
 
Aside from perhaps _Incisasaurus_, what maniraptors used their teeth as display 
structures?
 
 
> The loss in the ancestors
> of Neornithes may in fact have been the last one and apparently happened
> in the Late Cretaceous (using the oldest occurrences of Ichthyornithes,
> the closest relative of Neornithes with known jaws, to estimate the age
> of the MRCA of Ichthyornithes and Neornithes).                                
>