Re: Abydosaurus mcintoshi, a new sauropod from the Albian of Utah

[Tim Williams <tijawi@yahoo.com>]

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


> I would be seriously interested in seeing Lusotitan, Europasaurus, 
> Sauroposeidon, Paluxysaurus, and Astrodon thrown into the mix!


Further, although there is no overlapping material between _Abydosaurus_ and 
_B. altithorax_, there is a brachiosaur skull from the Morrison Formation.  
This is USNM 5730, from Felch Quarry 1, Colorado, described by Carpenter and 
Tidwell (1998).  (This is the skull that was once thought to belong to 
_Apatosaurus_, and the source of old _Apatosaurus_ reconstructions that showed 
it with a _Camarasaurus_-like skull.)  There is no overlapping material between 
USNM 5730 and _B. altithorax_, so it is not known if USNM 5730 belongs to 
_Brachiosaurus_.


In any case, USNM 5730 is substantially different to the skull of 
_Giraffatitan_, and in some ways intermediate between the skulls of 
_Camarasaurus_ and _Giraffatitan_.  It might be useful to add USNM 5730 to the 
phylogenetic analysis as well.  Sure, it's only known from skull material; but 
_Nemegtosaurus_ and _Quaesitosaurus_ are likewise known only from cranial 
material, and have been included in titanosaur matrices.


Cheers
Tim