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Re: Microraptor ate birds


> From: Robert Schenck <schenck.rob@gmail.com>
>>>It's definitely intriguing, and IF microraptor et al were arboreal, it is 
>>>what we'd
>>> expect.
>>The hypothesis is not well-thought out, and not based on any modern 
>>comparisons (hence, I predict it will be published in Nature, or ProcB).
>Should we really expect there to be good comparisons though? I'll
agree that the lack of modern analogs isn't meaningless, but how much
weight should we give it? 

I don't think it would be beyond reason to do a little survey of extant 
predators that eat "arboreal" birds, and see just how regularly said birds are 
caught in trees as opposed to on the ground. This wasn't done, merely an 
assumption was made (not the least, the assumption of arboreality on the prey's 
behalf). I understand this is a poster, not a peer-reviewed paper; these sorts 
of conclusions shouldn't make it into print without a proper assessment of the 
data, but frequently we see misinformation making it through. The original 
Microraptor gui description had a reconstruction of a splayed-limb glider -at 
odds with known anatomy of dinosaurs; indeed the upright unsplaying hindlimb is 
one of THE dinosaurian features emphasized in the most basic undergraduate 
classes on dinosaurs; I can;t understand how this was missed by both 
researchers and reviewers alike. This poster is further illustrative of the 
glider-first argument being based on poor reasoning,
 purely hypothetical models, and weak knowledge of anatomy and ecology, that 
somehow gets into big journals.

>Anyway I'll agree that the positive evidence for arboreality in
Mesozoic dinosaurs doesn't seem to be out there, but if they were
arboreal predators, then, yes, preying on other arboreal species could
make sense.

Make sense? part of this thread suggested trees were some sort of refugium from 
predation, now apparently the opposite makes sense. This is where surveying the 
extant ecological literature makes more sense.

>> It's not behaviour: it's diet. For all we know, the Microraptor might have 
>> found a dead bird on the ground.
>Absolutely, could've come from the ground. It's still behaviour of
course, my point is that its something other than osteology, which is
allways nice. 

Yes, it's paleobiological data. Evidence of some trophic interaction. This part 
is very interesting. I like the point made by someone else that it is little 
different from finding fish remains in confusciusiornithids: does this mean 
they were waterbirds that always eat fish? what is the variability in diet of 
carnivorous birds anyway? Do they eat the same food all the time, caught the 
same way, or a variety of different prey types, caught different ways and 
places? what is the difference between catching prey and killing prey? Does the 
bald eagle only eat fish? What does a cosmopolitan diet mean? None of this is 
addressed; just leaping to conclusions about arboreality without trying to test 
a hypothesis, or even survey possible corroborating data.

Denver Fowler