Re: T. rex the Hunter

["Matthew Troutman" <m_troutman@hotmail.com>]

>Let me begin by saying that I greatly respect John R. Horner, but 
disagree
>with his characterization of _Tyrannosaurus rex_ as being primarily an
>obligate scavenger.

    I too respect Jack Horner, not only for his paleontological 
accomplishments, but for his knowledge in biology ( which he didn' t 
need a college education for ). 

  I am only commenting further on this subject because I
>have new information to bring to the discussion.

    And what new information it is.


>Within the interview, I am surprised that John Horner should say the
>following:
>
>"There is also a duck-billed dinosaur that was apparently bitten in the
>tail by a _T. rex_, and again I haven't a clue why that would preclude 
_T.
>rex_ as a scavenger."

    I believe his point was that he does not see why that since T.rex 
occasionally fed on live animals why this proves T.rex did not scavenge 
for the majority of the time.

>I would presume that he is speaking of the _Edmontosaurus_ (DMNH 1493)
>which features _healed_ bones along the back of the tail, so the 
healing of
>the wounded bone is, of course, the reason why this specimen is 
considered
>to provide evidence of hunting on the part of _T. rex_.  If Horner has 
been
>apprised of the nature of this specimen, what has led him to his point 
of
>view regarding its pertinence to the debate?  

    See above.

>One of Horner's main arguments concerns the use of smell in locating 
food. 
>He states: "Also, _T. rex_ had a huge olfactory lobe in its brain, 
which is
>an organ for smelling (sic), and the size of it suggests that _T. rex_
>could smell things far in the distance, which is only advantageous if 
what
>you are after isn't going anywhere."

     I can see Horner's point. New World vultures that live near 
forests, such as the turkey vulture, use their oversized olfactory lobes 
for sensing carrion. This is because of the habitat in which these live 
in is not very kind on vultures that live in open areas. Since T.rex 
lived in forested, closed areas, I see no reason why it shouldn't evolve 
such a feature. 

>In the past, John Horner has frequently invoked the analogy of the 
3-pound
>turkey vulture, one of the few birds with a good sense of smell (the 
kiwi
>being another).  I propose a different modern analog: the 53-ton sperm
>whale!  It is the largest extant predator (excluding filter-feeding 
baleen
>whales, which clearly don't compare with theropods at all), and, 
wouldn't
>you know it, it has the largest olfactory organ of any known animal, 
living
>or dead!  Unlike the tyrannosaurid, it is a swimming animal, but, like 
a
>tyrannosaurid, it has no forearms and grabs prey with huge jaws which 
are
>studded with robust teeth (although, unlike a tyrannosaurid, the whale 
only
>has teeth on the mandible).  A recent National Geographic special, 
called
>"Sea Monsters: In Search of the Giant Squid," displayed a computer 
graphic
>illustration of the whale's internal anatomy, and computer graphic
>animation showing how the whales might pursue and catch giant squids.

     That is certainly a worthy and compelling comparison.

   

>Ralph Miller III <gbabcock@best.com>
>_Moby rex_? 
>
>

 My regards,

MattTroutman

______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com