RE: had a thought - dimorphic tyrannosaurs? was RE New fossils provide clues to tyrannosaur/ornithomimid evolution

[Tim Williams <tijawi@yahoo.com>]

Thomas R. Holtz, Jr. <tholtz@umd.edu> wrote:

> However, there is now a very good history for both the ornithomimosaurs
> (going back to the Early Cretaceous) and the tyrannosauroids (back to
> the Middle Jurassic), and they are separate and distinct
> throughout that time.


It's interesting how these new basal tyrannosauroids pull previously 
non-tyrannosauroid taxa into the clade, as other basal tyrannosauroids.  This 
time, _Proceratosaurus_ comes out as a basal tyrannosauroid (Makovicky et al., 
2009).  In one previous analysis it was _Coelurus_ and _Tanycolagreus_ that 
were recovered as basal tyrannosauroids.  (Makovicky et al. [2009] are close: 
these two come out in a sister taxon to the Tyrannosauroidea + 
Maniraptoriformes clade, which I guess would be Tyrannoraptora).  


Also, this same analysis recovers _Falcarius_ outside the Therizinosauroidea, 
in a much more basal position relative to other maniraptorans.  Even though the 
bootstrap support would seem to be weak (based on the cladogram), I find this 
position VERY interesting.


Cheers

Tim