Re: Haplocheirus and Gregory S. Paul

[Tim Williams <tijawi@yahoo.com>]

Mark Pauline <markpauline@rocketmail.com> wrote:


> The analyses of Haplocheirus that
> I've read focus on dispelling any vestiges of the "temporal
> paradox". It occurred to me, though, that this animal also
> has strong implications for Birds Come First or modified BCF
> hypotheses (like Gliding Paravians Come First).


BCF died a long time ago.  Darren Naish pronounced the last rites in his 
brilliant Tet Zoo blog, where he explicitly refuted BCF.  Though by this time 
it was obvious that BCF was unsupportable (and always had been).  When 
discoveries such as _Haplocheirus_ turn up, all that's left to do is grab a 
stick and prod the BCF corpse one more time.


Also, as I'm sure you're aware, GSP's hypothesis is much more conservative than 
BCF.  The latter was conceived by somebody else, and is far more radical in 
proposing that ALL dinosaurs (even sauropods and ornithischians) evolved from 
ancestors that were arboreal and (in the case of theropods) glissant as well.  


> The basalmost Therizinosauroid,
> Falcarius, and the basalmost Oviraptorosaurid,
> Incisivosaurus, also seem to be primitively big and non -
> aerodynamic. This suggests that the most primitive
> maniraptorans that could glide or fly were paravians, and we
> have basal members of each of the three main paravian
> lineages to prove that they did, all from the Jurassic or
> Early Cretaceous.


I'd agee with you up to the point about oviraptorosaurs.  _Protarchaeopteryx_ 
is only about 1m long (including the fairly long tail), and the skull of 
_Incisivosaurus_ is about ~10cm long.  So I wouldn't call these basal 
oviraptorosaurs especially large.  If an Oviraptorosauria-Paraves clade is 
supported (to the exclusion of alvarezsaurs and therizinosaurs), I'm open to 
glissant/scansorial behavior being primitive for this clade.



Cheers

Tim