Re: taxonomy is not stratigraphy (was Re: JVP 25(2): New Dinos, Birds, Discoveries)

[don ohmes <d_ohmes@yahoo.com>]

>>>> Tim Williams wrote: Even the largest of
titanosaurs were small when
they
were young.  BTW, it's 
my personal opinion that theropod predators
(including tyrannosaurs) 
typically targeted the smaller or weaker members of
a sauropod herd anyway, 
and avoided the larger and stronger individuals. 
This would be more in 
keeping with the behavior of modern predators.<<<

Assuming titanotheres were selected for size by
predation: is there a contemporaneous predator large
enough to tackle them one on one? If not, this would
support a pack strategy for a smaller top predator.

--- Tim Williams <twilliams_alpha@hotmail.com> wrote:

> Tim Donovan wrote:
> 
> >   Brochu said TMM 41436-1 was T. rex or a close
> relative. The latter is 
> >probably true given the age of the Javelina and the
> relatively small size 
> >of TMM 41436-1. (Carpenter also mentioned a short
> face compared to T. rex.)
> 
> A more recent paper dealt with this.  TMM 41436-1 is
> probably _T. rex_.
> 
> >It must have been a smaller ancestor of T. rex.
> 
> Why "must"?
> 
> >No wonder its tyrannosaurs were rather rare and
> Alamosaurus so common.
> 
> Actually, as pointed out in previous postings,
> _Alamosaurus_ is a 
> wastebasket/dustbin for LK titanosaur material from
> North America.  Several 
> titanosaur taxa may in fact be represented across
> the southern U.S.A.
> 
> >They hadn't yet evolved the size necessary to take
> on the titanosaurs in an
> >environment dominated by them.
> 
> Even the largest of titanosaurs were small when they
> were young.  BTW, it's 
> my personal opinion that theropod predators
> (including tyrannosaurs) 
> typically targeted the smaller or weaker members of
> a sauropod herd anyway, 
> and avoided the larger and stronger individuals. 
> This would be more in 
> keeping with the behavior of modern predators.
> 
> Cheers
> 
> Tim