Re: Oh, yeah, the reference...

[Tim Williams <twilliams_alpha@hotmail.com>]

Roberto Takata wrote:

> > First up, a salvo against the BANDits...  However, Feduccia &c appear 
> now to
> > be arguing that birds and maniraptorans are indeed closely related, but 
> that
> > they are NOT theropods or dinosaurs.
>
> When Feduccia et cols intend to strip Maniraptora out of the Theropoda
> clade, are they proposing that e.g. _Velociraptor_ is not a theropod?

Apparently, yes.  I think Feduccia has hooked into the Czerkas-Martin school 
of thought, which proposes a diphyletic Theropoda: (1) a Maniraptora-Aves 
lineage and (2) an everything-else lineage ("true theropods", like 
coelophysoids, allosaurs, tyrannosaurs, etc) with both lineages evolved 
separately from an undisclosed ancestral stock.  But, these authors are 
never entirely clear on the dividing line between Maniraptora-Aves and 
"true" theropods.  To which group do ornitholestids_, compsognathids, 
alvarezsaurids, and ornithomimids belong, for example?  The BAND crowd is 
vague on this issue, as with many other issues.

And, as David says, their articles tend to contradict each other.  After 
arguing for decades that the similarity in bauplan between dromaeosaurs and 
_Archaeopteryx_ was due to convergence, this crowd now accepts that the 
similarities are the result of a close relationship - but they now argue 
that the similarities between dromaeosaurs and non-maniraptoran theropods is 
due to convergence!

I wou'dn't worry too much about all this.  This is the last hurrah! of the 
BAND movement.  It has all the hallmarks of a desperate rearguard action.

Roberto Takata also wrote:

> Changing the subject a bit: Therizinosauria and Segnosauria aren't
> regarded as synonyms anymore?

AFAIK, neither Therizinosauria and Segnosauria have received phylogenetic 
defintions, though Therizinosauroidea has.  I would say that Therizinosauria 
and Segnosauria can be regarded as synonyms, given that they are effectively 
equivalent in content and concept.

Cheers

Tim