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Re: Questioms from James Carey?



Stephan Pickering (stefanpickering2002@yahoo.com) wrote:

<Jim Carey -- whose paper on dinosaur parental care will, in time, be the
basis of an extensive study of various questions -- has sent me some
questions which I'll outline here for possible discussion.>

  If you could, what were his actual questions?

<1. The new Microraptor shows that, ground-dwelling (predation risk) would
have been difficult, and that tree-living (or in burrows on the sides of
cliffs, e.g.). Unlike most dinosaurs, thus, it "nested" in trees >
incipient parental care.>

  Don't see how *Microraptor* was at any greater risk of predation than,
say, *Sinosauropteryx* which, judging from its short arms and similar
length, was as small and probably more or less terrestrial. This may or
may not have led to incipient parental care, even in birds, which is
plesiomorphically (as pointed out by Hopp and Orsen) ground-based; there
is direct evidence of parental care of the nest in *Citipati* which is
ground-based.

<2. Do the teeth of any of the Microraptors show patterns and morphologies
from which one could infer nesting building capabilities and/or feeding
altricial young?>

  They were good at killing things? There were large predatory teeth. I
would assume that nest building was aided, as in most birds, by a
combination of foot (read: & hand) and mouth, just as in crocs. If it
built nests. Not exactly a provable thing.

<3. One wonders if these small dinosaurs were raised through "fledgling"
stages. Do any of the feathered dinosaur fossil show any indication of a
brood patch?>

  Any evidence of moulting bald spots? Not sure... Presumably some
theropods would have had bare undersides, but there is no evidence for
this, and all forms seems to suggest or do not indicate that the entire
trunk was covered. In *Citipati*, the entire trunk overlayed the nest, as
did the arms, unlike birds, during the actual nesting period. How this
translates to brooding behavior I do not know, and it is speculative to
suggest that any non-avian theropod had a brood patch when even many basal
extant birds, such as ratites, lacked them as well. And still brooded in
oviraptorid-style.

  Cheers,

=====
Jaime A. Headden

  Little steps are often the hardest to take.  We are too used to making leaps 
in the face of adversity, that a simple skip is so hard to do.  We should all 
learn to walk soft, walk small, see the world around us rather than zoom by it.

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)

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