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OCCAM'S RAZOR & THERIZINOSAURS
On that oft-discussed subject of where therizinosaurs fall out within
Theropoda, Pete Buchholz, he of the consistently misspelt name,
> Indeed, all saurischians have pneumatic vertebrae with pleurocoels.
> The point I believe Jim was making is that Brooks was showing that
> the pleurocoels of therizinosaur cervicals had vertebrae that were
> pneumaticised in a similar manner as those of Ornithomimids etc, not
> the simple invagination seen in Anchisaurus cervicals.
Clearly at the moment the extensively pneumaticised cervical
verts (and don't forget, with specific regard to this issue, that
Pete Makovicky - whose thesis was on coelurosaurian verts - supports
a close association of therizinosaurs and oviraptorosaurs),
coelurosaurian briancase wiring, maniraptoriform hands and wrists and
inflated braincase bones make it most parsimonious to regard
therizinosaurs as theropods: this is my view via simple application
of Occam's razor. Plus the fact that every theropod worker*, without
exception so far as I know, finds Therizinosauroidea nested somewhere
However, I honestly would not have expected the presence of a
therizinosaur in the Lower Jurassic. Does everyone advocating a
bullatosaurian or oviraptorosaurian affinity of therizinosaurs really
appreciate what this means?
(Or, is Chatterjee right??)
> Second. Coeluria should be regarded as a nomen oblitum because as
> far as I know, only Marsh and George have ever used the name
GSP used it too, in PDOTW. And I don't *think* 'forgotten name' rules
apply to higher taxa. Is this correct? Having said that, I do not
disagree with Pete as to the idiosyncratic use of Coeluria.
*By 'worker' I am referring to all those palaeontologists who have
published technical descriptive studies of members of Theropoda.
"Ok.. who's next?"