[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

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

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

> Tim Donovan wrote:
> >P. Currie mentioned healed bite marks on sauropod
> bone from the Morrison, 
> >IIRC, suggesting that even early theropods attacked
> sauropods capable of 
> >defending themselves.
> Well, I'm not suggesing that the predator had a 100%
> success rate.  Even 
> weak and sick prey manage to escape sometimes.

  Maybe not often enough to be represented in the
fossil record. :)

> >  Giganotosaurus and Argentinosaurus,
> >Carcharodontosaurus and Paralititan,
> >Torvosaurus/Epanterias and Brachiosaurus etc.
> Starkov mentioned other 
> >examples.
> This reprises some of what Denver said: just because
> a given habitat 
> includes both a very lage predator and a very large
> herbivore does not 
> necessarily means that the former specifically
> targeted the latter.  
> Medium-sized predators may have sought prey larger
> or close to the size of 
> themselves (e.g., _Velociraptor_ vs _Protoceratops_;
> _Deinonychus_ vs 
> _Tenontosaurus_, maybe).  Large predators may have
> sought prey much smaller 
> than themselves.  

  Certainly not invariably in the case of
tyrannosaurs. There are healed bite marks on
Triceratops, ankylosaur and hadrosaur bone.

>There is a chapter in the new
> _Carnivorous Dinosaurs_ 
> volume dedicated to this issue.  I think Starkov's
> one-on-one predator-prey 
> match-ups are too simplistic.
> >  Yes, but Tarbosaurus was smaller than T. rex,
> Not by much (if at all).

 See the illustrations in The Complete T. rex. Even
PIN 551-1 had a skull only 1.35m long vs 1.5m for T.
rex. UCMP 118742 and a more recently discovered
specimen may have been even larger.

> >Based on that, and the Tyrannosaurus-like TMM
> 41436-1 in a titanosaur 
> >dominated mid Maastrichtian environment, it appears
> that Starkov is right 
> >about the origin of T. rex. Like
> >previous theropod giants, it apparently arose in
> response to large 
> >sauropods.
> Or vice versa.

  I doubt it. Sauropods were already present in NA by
the late Campanian, well before T. rex or its closest

Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around