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Re: Microraptor ate birds
Am 11.11.2011 17:40, schrieb Denver Fowler:
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;
SVP meeting abstracts do get reviewed, though. And 30 % or more of them
are rejected. (No more T. R. Karbek on bipedal cursorial stegosaurs,
alas.) Of course, the reviewers have only the submitted abstract to go
with, not the unpublished evidence that supports it, but this abstract
should have raised questions...
Or maybe the reviewers figured any excuse for showing us that specimen
was fine. I'd understand that. :-)
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.
What you say is true but not a very good argument. Autapomorphies
happen; in this case, a few specialized reed-living passerines can
indeed sprawl.
A better argument is that horizontal hindlimbs are at odds with the
known anatomy of _*Microraptor*_. Given the description and photos by
Hwang et al. (2002), the describers of *M. gui* should have been
requested to explain (at the very least in the supplementary
information, which isn't under space restrictions!) why they thought *M.
gui* was capable of such sprawling -- other than being used to mammalian
anatomy (femur with spherical head and long, pinched neck) and having
encountered the "Tetrapteryx" hypothesis.
BTW, is there a detailed description of *M. gui* in the works? That
4-page Nature paper is all that's published.
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?
This was proposed at the zoology conference in Paris a few years ago by
A. Zinovi"e"v. He thinks this is what a fish-eating bird that lives in a
place with trees and cannot lift off from the ground looks like.
However, I wonder about the beak shape and the surprisingly robust
skull. (The beak isn't very long, and it has completely straight margins
that don't seem good for catching anything slippery.)
what is the difference between catching prey and killing prey?
Falconids usually catch prey, then kill it (very quickly) if the impact
didn't already kill it, then eat it. Accipitrids usually catch prey,
then (if the impact didn't kill it) only kill it by eating it -- while
flapping a lot to stay on top of the prey, a fact I should have
remembered (from a previous SVP meeting) for another thread.
Bears kill salmon by ripping them apart and eating them, as seen on TV.
Snakes kill dangerous prey. Harmless prey, and poisonous prey that
doesn't get less dangerous by dying, they swallow alive.
Most frogs catch prey by swallowing it. True toads don't even have any
teeth, nor the fake teeth found in the lower jaws of some frogs like
*Hemiphractus* that eat large, dangerous prey.
Does the bald eagle only eat fish?
Rhetorical question, right? It's a generalist scavenger in addition to
catching fish.