Re: BAD vs. BADD (was: Re: Most popular/common dinosaur misconceptions)

[Tim Williams <twilliams_alpha@hotmail.com>]

Jura <pristichampsus@yahoo.com> wrote:

> Well, for one, birds locomote in a manner completely different from those 
> of dinosaurs (classic dinosaurs).I'm not talking about flying either. No 
> dinosaur has been shown to be a tibia based walker.

Did _Archaeopteryx_ walk in the avian manner?  Did _Confuciusornis_?  
_Sinornis_?  Basal avians actually have very similar hindlimb proportions to 
non-avian theropods.

And how would we know if they did walk in an avian manner?  How do you 
propose to use terrestrial locomotory posture as the criterion for 
classifying a theropod as a bird (Aves) when this cannot be observed for 
those theropods closest to the origin of Aves?  As the example of 
_Caudipteryx_ demonstrates, locomotory posture is exceedingly difficult to 
calculate, and ultimately impossible to demonstrate.

> In all honesty the only grey area that I've ever seen with birds and 
> dinosaurs involves a small set of
> maniraptors and very early, (archaeopterigiformes and such) birds.

That the 'gray area' exists at all tells you how useless and misleading 
Linnaean ranks are.

> You keep arguing the semantics, but seem to be missing my point. No one 
> goes around using these "non-" monikers anywhere but in vertebrate 
> paleontology

Wrong.  I've seen invertebrate zoologists use them, for example.  (See 
below.)  I cited the example of annelid phylogeny, after three 'phyla' 
(Echiura, Pogonophora, Vestimentifera) were sunk into the Annelida, giving 
us terms such as non-siboglinids annelids, etc.  I've also seen 
"non-strepsipteran insects" mentioned.

> Besides, Prokaryota is an acknowledged group, even if it was never included 
> as a clade.

Prokaryota is almost universally acknowledged among microbiologists as being 
useless and misleading for phylogenetic purposes, given that bacteria and 
archaea are no closer to each other than they are to eukaryotes.  Refer to 
Woese's "Three Domain" hypothesis.

> Interesting, the papers you mention only very quickly use the "non-" 
> moniker, before replacing it with an actual term.

A descriptive and non-phylogenetic term, yes.  But that's beside the point.  
The fact is that invert zoologists DO use phylogenetic terms like 
"non-siboglinid annelid", contra your assertion that this phenomenon is 
limited to vertebrate paleontologists.

Cheers

Tim