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Re: T-rex could kick



Nick Longrich wrote:

>         Secondly, the head has all the firepower. It is powerfully
> constructed, four to five foot long, with teeth a full foot from root to
> crown. Those jaws could punch through solid bone, break vertebrae in half,
> leave bite marks in Triceratops bone and even punch through the head of a
> Triceratops femur.
>         There's your primary weapon.

In a fight, speed matters a lot.  I think _Triceratops_ was so much
snappier than _T rex_ that this approach would have been suicidal.
(I've decided the term "snappy" is less confusing than "agile.")

Here's Mickey's airplane analogy last November 8: "Which of the two
aircraft is more maneuverable?  The Dr-1.  It can make much tighter
turns at low airspeeds where the F-16 wasn't designed to operate."

The Dr-1 was a faulty imitation of a British model.  Test pilots agreed
with Mickey.  The Sopwith Triplane would "turn on a shilling and give
sixpence change."

I'm sure a biplane could fly as small a circle as a triplane.  In
practical terms, the triplane could turn quicker because it could snap
into and out of turns faster.  Its wings could tip faster because they
were a little shorter than biplane wings.

A glider can fly in a small circle, but it takes so long to tip the long
wings up and down that circles look like 9s and 6s.  In crop-dusting,
short wings are used because a snappy response matters much more than
low drag.

I used to skate with my younger brother one winter before he reached his
adult height.  I was faster, and, because I took the trouble to keep my
skates sharp, I could lean way over to pull turns he couldn't match.

However, his center of mass was perhaps 10 percent lower than mine,
which meant it didn't have to move as far to lean into a turn.  Because
of this, he could snap into and out of turns much faster than I.  In
games of tag, I sometimes ended up with my head in a snow bank because
he could snap a turn in the time I could only imagine it.

As a fifth-grader, I felt like a big-leaguer because I owned and used a
37" bat.  I was dismayed to learn that big-league bats were only about
33", which meant I wasn't at all professional!

The difference was in the available time.  A pro needed a snappier bat
because professional pitching was faster and more confusing.

A bigger bat would have the momentum to knock more hits over the wall.
Some pros are so powerful that they break bats with practice swings.
They have the muscle to get a snappy response from a bigger bat, but
there's another problem.  If they swung a bigger bat that sharply, the
equal and opposite reaction would knock them down.

This represents a problem bipeds have.  In some moves, a quadruped may
be better at overcoming the inertia of length and mass because the
quadruped's geometry may allow it to resist the equal and opposite
reaction better than a biped.

A bull's geometry allows its muscles to force some terrifyingly snappy
movements in spite of its mass and fairly long dimensions.  Because a
bullfighter lacks the geometry to match a bull's lunges and sprints,
he's betting his life on his ability to manipulate, anticipate, and
exhaust the bull.

_Triceratops_ seems to be built like a rhino, which, I understand, is
even snappier than a bull.  _T rex_, on the other hand, had a much
higher center of mass, much longer legs, a much longer spine, and
bipedal geometry.  It may have been a fast runner, but that's not the
same as being snappy.

I think a tyrannosaur who approached _Triceratops_ to try to bite or
kick would have been in the same predicament as a mouse trying to steal
cheese from a trap.  SNAP!

I wonder how many mistakes I made this time!

- Stephen Throop