On Mar 4, 2012, at 9:47 AM, Dan Chure wrote:
While the failed nest raiding is possible, I don't see how it can be
invoked if there wasn't a nest at the site. I understand that there
might have been a nest nearby that wasn't preserved but if you have no
evidence that there was a nest where the V-P were found it makes no
sense to build an interpretation around its being there. The same
general region preserving nests is not the same as a nest at the site.
There are many Protoceratops found that are not on nests or a nesting
sites. So the lack of a nest might be taken as evidence, although maybe
weak, that falsifies the nest raiding hypothesis.
I used to take that same perspective myself, actually. I do agree that nest
raiding cannot be supported as a specific hypothesis; I was using it more to
make a point than anything else. Without a nest preserved, I fully admit that
it is speculation to claim nest raiding, specifically. However, I think it
still makes the point that there are other scenarios that could lead to the
combat in question. Why should we consider them? Because the circumstances of
the fossil should make us immediately skeptical of a predation hypothesis. At
the very least, we should be extremely skeptical that this was a typical or
Look at this way: if the fossil in question preserved two extant taxa, in a
similar situation and size ratio, we would be much more confident that the
predator screwed up, at the very least. For some reason, the strong preference
bias for small, juvenile prey among even quite powerful modern predators
doesn't get its due when we examine the terrestrial fossil record.
The development of a slicing claw and the attendant morphologies seems
to be an odd adaptation if V (and its relatives) regularly fed only on
prey smaller than itself.
Why? Most living terrestrial predators, including animals as powerfully armed
as cats and birds of prey, hunt animals smaller than themselves. Even if the
claw as truly a slicing structure (and it might not have been, although it's
certainly plausible), I don't see why that is incompatible with feeding on prey
that is relatively large in ecological terms, but still smaller than the
predator (say, for example, 50-66% the size of the dromeosaur).
I realize that I am going out on a limb a bit - my point is not that my speculative
hypotheses here are necessarily better, but rather that the "super-predator"
models so popular in paleontology have not received due skepticism. If we can really,
truly shore them up then that's great - but it should be recognized how extraordinary it
would be to have a wide range of predators attacking prey much larger than themselves.
Assistant Professor of Biology
Woodland Road, Pittsburgh PA 15232
Buhl Hall, Room 226A
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