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

[Tim Williams <twilliams_alpha@hotmail.com>]

Denver Fowler wrote:

> >  Maybe. But, as Starkov noted, there is a correlation between the rise 
> of the largest sauropods > and largest theropods, suggesting the latter 
> became bigger to overcome more massive prey.
>
> this makes the assumption that adult tyrannosaurs attacked adult 
> titanosaurs which is rather unlikely.

Agreed.  Unless the adult titanosaur was wounded or sick.

Tim Donovan wrote:

>  Maybe. But, as Starkov noted, there is a correlation between the rise of 
> the largest sauropods and largest theropods, suggesting the latter became 
> bigger to overcome more massive prey.

I haven't read any of Starkov's stuff, but I'm inferring from your statement 
that he is claiming that the largest sauropods co-existed with the largest 
theropods.  Although it's an intuitively attractive idea, I don't believe we 
have the data to back it up.  For example, _Tyrannosaurus_ was a very large 
theropod, but _Alamosaurus_ was not that impressive by sauropod standards.  
Similarly, the Nemegt sauropods were not spectacularly large, and these were 
the guys who rubbed shoulders with _Tarbosaurus_.  All post-Triassic 
terrestrial Mesozoic habitats were probably home to theropods and 
dinosaurian herbivores of different shapes and sizes; but I don't think we 
can pair up the carnivores and herbivores based on size alone.

Cheers

(The other) Tim