Re: tyrannosaurs and sauropods

["Timothy Williams" <twilliams_alpha@hotmail.com>]

Raymond Ancog wrote:

> Stephen and Sylvia Czerkas hint at a possible encounter between
> tyrannosaurs and sauropods in their book "Dinosaurs: A Global View." In the
> Late Cretaceous, N & S America were briefly connected, and possibly Eurasia
> and Africa. That would have allowed the northern tyrannosaurs to migrate to
> the south and meet the sauropods

As far as I know, there's no good evidence that _Tyrannosaurus_ lived in the 
southern USA.  _Tyrannosaurus_ bones in the South are about as rare as 
Democrats, and any material (like the maxilla from Javelina/Tornillo Fm of 
Texas) is dubiously _Tyrannosaurus_.  There are tyrannosaurid bones from New 
Mexico (?Maastrichtian), currently referred (provisionally) to _Aublysodon_. 
 The material is so badly preserved that it COULD be subadult _T. rex_.

Recent cladistic analyses seem to suggest that _Alamosaurus_ is most closely 
related to S. American titanosaurs like _Saltasaurus_.  But _Alamosaurus_ is 
a poorly known genus, and since there are at least two Early Cretaceous 
titanosaurs from N. America (_Pleurocoelus_ and one to be named), there is a 
possibility that _Alamosaurus_ was home-grown.


Tim


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