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Re: Tyrannosaurid Growth Spurts



John Hunt (john.bass@ntlworld.com) wrote:

<There was a recent programme on National Geographic that showed a pride
of lions attacking an adult elephant, which may be analogous to a flock of
therapods attacking a sauropod.  However, lions are atypical of big cats,
and one could wrongly assume that because lions show social behaviour, all
big cats do.>

  Use of the lions as social examples is provided simply because of this
social example, not because one wants to include cats in the list of
socially hunting mammals. The behavior of a hunting pride of lionesses or
male lions is similar to that of other terrestrial mammals to some degree,
allowing some universal parallels to be made, but this is not extrapolated
into the rather solitary remainder of cats in the wild, or even
domesticated ones.
 
<It has been suggested that the giant birds of prey that inhabited New
Zealand at the time humans settled there preyed on Moa's, and also on the
early human settlers.>

  The giant eagles of New Zealand -- related to the Harpy and Philipine
Monkey-Eating Eagles -- were probably like other living eagles, in being
largely solitary. Even pair bonded eagles don't hunt together for the most
part, and two giant eagles swopping down on a single moa or human might
get in one another's way. 

<There have been numerous studies of the locomotive abilities of adult T.
rex, but have similar studies been done on juveniles or adolescents?>

  A complete enough skeleton for a much smaller *Tyrannosaurus rex* are
undescribed to date. Those in-prep specimens are being worked on right
now, including "Tinker," but this information can be largely anticpated:
juveniles for other large tyrannosaurids, incuding *Albertosaurus,*
*Gorgosaurus,* and *Tarbosaurus* ARE known and have either been studied,
or described, for the purpose of mass, at least. It is likely that
*Tyrannosaurus* juveniles did not differ from the juveniles of other
tyrannosaurids as much as the adults did, as is common among
closely-related groups of birds, mammals, reptiles, etc.

<If T.rex used the bite and wait strategy evidenced by Ken Carpenters
hadrosaur with the T.rex bite, that probably should have died from shock
and infection with such a wound, they would only need to get close enough
to bite the tail.>

  I wouldn't say the hadrosaur specimen at the DMNS is evidence of a
hunt-and-wait strategy, as the hadrosaur lived after the trauma to its
tail was inflicted, and was healed. Mode of its death is so far unknown,
but it survived the attack or contact that caused the damage to the tail.

<Changing the subject slightly, and following the recent Archaeopteryx
brain scan, T.rex has been the subject of CT scans that have been used to
compare its olfactory abilities with vultures, but are there any other
similarities between the T.rex and vulture brains?>

  This HAS been done: Chris Brochu, a few years back, described a CT scan
of the skull of Sue, but the olfactory bulbs are not so clearly seen as
one would like, and the actual volume of the olfactory nerves themselves
is incomplete. However, the really important issue may be the comparative
study of olfactory bulbs to brain in OTHER animals. Especially since one
of Horner's evidences has been to say that the olfactory region is so much
larger than the optic region, despite the retention of a tennis-ball-sized
eyeball, it could hardly see worth damn, but sure as hell it could smell.
Other animals with a relative proportion of optic and olfactory
specialization are unknown to date because the study sampling has NOT been
done: this information is NOT given to the public, or described in the
documentary "Valley of the T. rex," even though it is critical
information. I'm hoping Horner is working on this, but fear someone else
or a group may need to look into this data. Does a giant olfactory system
mean you are a nose-first animal, not eye-first, and that you're a
scavenger? Important questions that have not been answered, and are
needed.

  Cheers,

=====
Jaime A. Headden

  Little steps are often the hardest to take.  We are too used to making leaps 
in the face of adversity, that a simple skip is so hard to do.  We should all 
learn to walk soft, walk small, see the world around us rather than zoom by it.

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)


        
                
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