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Re: [Re: Non-serpentine lacertids (was RE:WHAT'S GOING ON?)]

"T. Mike Keesey" <tmk@dinosauricon.com> wrote:
> On 3 Jul 2000 archosaur@usa.net wrote:
> > I'd love to do that, but if I were to ask Mark Norell what he thought
> > dinosaurs might sound like, I have a feeling that he would start > >giving
me a list of songbirds.
> So specify "Mesozoic dinosaurs".


That's kinda the point though. Birds diverged enough from basal dinosauria
that they warrant their own class status (yeah I know arbitrary, arbitrary
arbitrary). If I were to ask Norell what he thought dinosaurs sounded like I
would expect an answer that dealt with true dinosaurs (Eudinosauria?). 

I'm sure that is going to get misconstrued. What I mean is all dinosaurs that
don't meet all the criteria to be a bird.

In the same respect, I would think that if I asked someone what therapsids
sounded like, I wouldn't get a list of dogs,cats, rats, ferrets, horses and
other mammals.


> > But isn't _Sphenodon_ also a non-serpentean lepidosaur? That's why I >
>tried to keep it narrower.
> Sorry, I *should* have said "non-ophidian squamate".
> > Regardless, the point I'm making is that snakes evolved from >
>lacertilian (saurian) stock, but rather than calling them modified > >
>saurians or what not, we have given them a separate name which makes >
>distinguishing between them a lot easier. 
> It's the same case with birds. They have a separate name which
> distinguishes them (Aves). But they are still part of Dinosauria, just >as
Ophidia is part of Squamata.


Okay then, now if people could just stop going around calling birds flying
dinosaurs, everything would be fine.

> > I'm not doubting their evolutionary roots, but I do have my > >
>reservations about calling such obvious birds, dinosaurs (the same kind > >of
reservations that I would have when calling a python a saurian or >
> Snakes aren't descended from Mosasauroidea; they're the sister
> group. Pythons are certainly saurians, though, as are crocodylians and,
> yes, birds!


Oh sure pick on the guy who was absent the day Sauria got moved from the
suborder of Squamata to the crown group of Diapsida.

Ok so I guess I would have qualms with calling a python a derived


> > > "Lizard" and "snake" are wholly vernacular terms.
> > 
> > And "bird" isn't?
> Certainly it is, and people can call feathered non-avians like
> _Caudipteryx_ "birds" if they want. But Aves is a formal taxon.

Well that actually had more to do with your catching me for using lizard and
snake, but letting me slide with bird. 

Again _Caudipteryx_ & _Rahonavis_ ARE the kinds of creatures that I think do
warrant calling non-avian, because that is where those arbitrary boundary
lines get fuzzy.


> > All pedantry aside, I hope you see my point. When there is no doubt as >
>to what category the animal belongs to, then use the name of said >
>category. When the animal can't be easily pidgeon holed, then use the >
>non-whatever names for them.
> > 
> > I mean does _Brachiosaurus_ really have to be called a non-avian
> No; it can be called a "dinosaur". You don't "have to" call it a
> "non-avian dinosaur" any more than you "have to" call it a
> "non-ceratopsian dinosaur", or a "non-mammalian tetrapod" or a
> "non-titanosaurid macronarian", or a "non-gymnosperman eukaryote", etc.


Non-gymnosperm eukaryote? Kudos for originality on that one. Though it got a
tad confusing towards the end, I think we're getting somewhere. 

If there really is no point to calling a dinosaur non-avian then why bother
with it (with exceptions, of course, for those select few dinos that do have
enough characters from both groups to warrant the term: ambiguous)?


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