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Re: Kickboxing Cassowary (funny)



Having now read Moreno et al.'s 2008 paper on Varanus, for which I
thank John Scanlon, it seems that small teeth and poor closing
musculature are not so bad for tearing pieces of meat.

There are differences between dromaeos and varanus, as the authors
note, in that the latter might have used sidewards neck movementens to
cut flesh chunks, an in this its relatively wide mouth helps (similar
to what happens in the shark, but with less mandibular adductor
force).

In deinos, whose skulls are more laterally compressed, perhaps
vertical movements of the head may have occupied the place of the
sidewars movements of Varanus. Theropod necks seem to be powerful, and
the prominent epipophyses of many of them, including Deinonychus,
perhaps are related to strongly pulling the head backwards. Perhaps
they would not need to take great chunks of flesh, alternatively.

Now, two things:

-Some may think that the enlarged pedal unguals of Dromaeosauridae
indicate a disruption with former modes of use of the ungual. However,
it seems that the variation in the ungual size seems quite continuous
in Dromaeosauridae when taken as a whole, so that the disruption in
feeding habits with respect to other taxons might not be great, at
least not in all dromeos.

-I think that "overdesign" thing for preferring hypotheses can be
problematic. For example, it can be said that the cheetah has not to
run as fast as 112 km/hour to outrun a gazelle which runs at 80
km/hour, less so even slower prey. However, fast catching the prey and
killing it is good as the predator avoids the time of exposure to
other predators willing to take its prey.

If it results that lions (Recent or fossil) can kill elephants, or
that sabertoothed cats just killed juvenile proboscideans (which lions
can also kill), then we should think that the sabertooth teeth is an
overdesign. However, the adaptation would help killing the prey faster
than the lion, no matter the fact that lion's tooth can also kill the
prey.

For the dromaeosaur, the ungual may have stabbed small prey well,
perhaps killed it soon, before it dared to bite, or some larger thief
appeared. "Overdesign" can save energy.