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Re: Tyrannosaurus tail torque

2010/11/18 Jonas Weselake-George <ee555@ncf.ca>:

> It may be valuable to think of additional factors beyond top speed.
> Some of the muscle mass may be optimised for endurance - with such long
> legs exhausting prey through "out walking" them may have been extremely
> effective.
Great idea, something similar to the canid approach. As far as I know,
canids are not faster than many of their prey item but can reach them
because of exhaustion. May the better developed air sacs of the
theropod give it an advantage in stamina than the less-developed air
sacs of most ornithischians? Better O2 capture, as produced by
unidirectional air flow may help getting more stamina for aerobic
prowess. But it seems ornithischians also had air sacs, judging from
their presence in both saurischians and pterosaurs. I am not sure if a
greater development of the air sacs means better O2 capture than in
taxa with smaller air sacs. Proportionally more voluminous air sacs
may imply greater flow of air per ventilation cycle, perhaps at
greater velocity if lungs do not change in size, and greater air flow
velocity may enhance the efficience of the counter-current diffusion
of O2 (for a given volume of air from which O2 is withdrawn at a given
point is faster replaced, thus diminishing the effect of diffussion
velocity decrease when O2 concentration in air and blood approach each
other). In any case, greater air sacs may have made Tyrannosaurus
lighter than an ornithischian of similar size, and this would give the
former a proportional advantage regarding velocity. In this case,
sauropods may also had great stamina (although this may be of little
use with a Tyrannosaurus). Stamina may be useful to sauropods if they
had to migrate like elephants from heavily foraged areas to less
exploited ones.

Tyrannosaurus also had titanosaurs and ankylosaurs to prey upon if
velocity or stamina was not their thing. May their greater estimated
bite force and banana teeth have something to do with specialization
into killing ankylosaurs? Ankylosaurids may kill or severely disable
with their blows, but bovids and suids can also kill -and sometimes
do- or severely disable with their horns and tusks, yet lions and
other predators still largely hunt them. Can we scientifically answer
how much efficient were ankylosaurid defenses against theropods in
comparison with the horns of bovids?