Re: Titanosaurus head & neck discovered in Chubut, Argentina

[Shawn Patrick Zack <spz@acpub.duke.edu>]

        At the risk of sounding even more out of the loop than I already am, 
what 
are the first three _Titanosaurus_ skulls known?  I'm guessing that one 
is the specimen from Madagascar mentioned in National History, but that 
still leaves two.  Any chance they're including _Antarctosaurus_ ?

        On a related note, I saw a blurb in the new Discover on a new 
brachiosaur from Arizona, "Sonorasaurus."  There's supposed to be a 
decent amount of it, including a partial skull.  The strange thing was 
the age, 100mya.  Is there much mid-Cretaceous material known from 
Arizona?  Has anyone haerd anything more about this critter?

                                --Shawn Zack
                                  the Duke dino