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Modern Inferences to the Scavenger/Predator Debate (Rehashing Old News for the Sake of an Overlooked Fact)



Dr. George J. Leonard wrote (quoting Horner):

< "The center of gravity for this 12000 lb dinosaur was twelve feet
off the ground, making it very unstable and an unlikely candidate for
rapid, agile moves...T Rex's arms are so short they cannot be joined
together, they cannot grasp themselves....Tiny eye sockets mean tiny
eyes and tiny eyes imply poor vision.  T Rex can't grasp, can't run,
can't see. Doesn't sound like much of a predator does it?.... If the
huge animal moved too quickly it might stumble to the ground, crushing
itself under its own weight... it would fall only once [for it
couldn't right itself? As I heard argued elsewhere.] T Rex.... was an
opportunistic scavenger, a connoisseur of carcasses, not an aggressive
hunter like Velociraptor.">

  Okay, this is really directed at Horner, but for now I'll use this
quote and pin it to my wall, where I shall throw many little darts at
it. [joke] Everything Horner wrote was refuted by Currie and Larson,
who are world experts in tyrannosaurs, as each object of Rex' anatomy
was shown to be corrollary and not specifying a scavenger. Eyes, arms,
head, olfactory nose, size, big lumbering lummocks with fat bellies.
<Belch!> Excuse you, Mr. Rex. <Belch! GRUUUNT!> Oops.

  However, referring to the title of the thread, and really cautious
about venturing into dead territory, I wish to point out one major
aspect of *Tyrannosaurus'* anatomy: the jaws. They are bone-crushing
devices, with a scalloping set of premaxillary teeth that are all
designed for crunching and pulling <huge> chuncks of meat and gristle
from bone, and really taking a big bite. Sometime last year I
estimated a tyrannosaur could fit about a 180lb. human man into it's
mouth, closed, and that you could slide down the throat with room
enough to fit between the pectoral girdle. Oh well, bottom's up! This
thing gulped food down. Yeah, scavengers do this, but guess what? Only
avian scavengers and jackals do this, with their narrow, small heads
and snouts, narrow delicate eating instruments at the tither end of
the digestive tract, rather than broad, thickened intruments or a
really wide jaw compared to height. That muscular equipment which Rex
had back of the eyes would have been capable of just about anything,
but especially what hyenas do. (Here we go again, another *T.
rex*/hyena comparison, but bear with me!)

  Hyenas have very broad jaws, huge robust teeth, and gigantic jaw
muscles, compared to either cats (well, lions and tigers come close)
and dogs. Most dogs (hell, most caniforms!) have narrow snouts and
slender teeth, great for plucking. Dogs attack using feet and jaws,
hyenas attack (that's right, not scavenge) using their jaws _alone_,
having to use the legs on running maneuvers in open territory (wolves
have cover, certain attack strategies, herding behavior etc. which
enables fewer numbers to take down big) and chase, and chase, and
chase, and finally kill by jaw action. The anterior very robust teeth
are used in the kill, and only the molars and premolars with canines
as braces are used in crushing bones. Vultures do not do this this
way, so are incomparable. Yet, Rex had much the same jaw structure and
tooth arrangement (if not morphology) most closely resembling to
hyenas among scavengers (well, birds don't count). Jaw arrangement
presupposes active use in methods other than stripping flesh quickly;
this can be done without such great jaw and muscular structure, as
vultures and jackals (the ultimate opportunists) tell us. So there was
something else in Rex's day besides belching decaying flesh.

  Skull size to maximize cranial performance and jaw power shrinks
arms. Head is the _only_ killing tool. Eyes are big, the size of
tennis balls (though they may seem small in comparison to the head)
and had enormous optic lobes with which to process a great deal of
visual data (vultures had big eyes, too, but see how they are in the
air and have to spot things from miles away?) so Rex had better
opportunity to catch sight of prey on the ground by being on the
ground, and bigger eyes one-up that chance. Big, robust dorsal
structure to support the neck and head, wide belly for support of legs
(to support body) and for the enlarged gut. <Yum! Yum!> I also
estimated, by volume measurements, that there were 20 cubic feet in
that gut and stomach, meaning, as all carnivores are fond of having,
that if that gut were completely full, _six_ men (of aforementioned
weight and general proportions of an average man of that weight, could
occupy it at once. <BELCH!>

  Such capacity and equipment belies a carnivore who actively preys on
available food items and to which vultures are _poor_ comparisons,
being aerial scaverngers on some species' parts. Sense of smell? that
one could be as effective as Horner estimates, but how far in distance
could a hadrosaur or ceratopian stink, whether alive or dead?

  My seventeen dollars and twelve cents.

==
- Often, it is the man who is brought
  down the path to the end who does
  not see his own steps. -

Jaime A. Headden

Qilong, the website, at:
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