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Re: Psittacosaurus adult found with 34 juveniles
The Psitticacosaur integument, on-line:
And mentioned in:
I was picturing the psittacosaur integument, described as ?bristles?, as
being similar to hedgehog bristles (spines): stiff, yet flexible. Or perhaps
they are more similar to Beipiaosaurus, only longer and thicker. Unknown at
Dann Pigdon wrote:
>Evan Robinson wrote:
> Although they might, the psittacosaurs presumably do not incubate their
> by sitting on them...
Perhaps not by sitting ON them - but a bristled tail wrapped around
them? I'm thinking of how wolves and foxes use their tails as 'blankets'
during cold weather.
Interesting idea. A large female cobra wraps her body around her eggs and
assists in egg incubation by flexing her muscles and vibrating. Of course
the Cobra?s eggs have leathery shells.! ?
How about those Early Cretaceous Hypsilophodontids down your way in
southeastern Australia? Do workers still think that a lack of LAG lines
indicates an elevated metabolic rate? (They were in the Antarctic circle at
the time). How do you suppose that they kept their eggs warm enough to
hatch? Is there any eggshell associated with them? No response required if
In response to issues rised to by Evan Robinson:
>>>It is possible that they all came from the one parent, the eggs could
have been mass shelled at the same time. The psittacosaurs may not have yet
fully developed the more avian ovary system of shelling one egg at a
I think it is likely that the eggs were all shelled at one time. I only
suspect that they cannot come
from one parent because they would have to be a tenth the size (if not
substantially smaller) to fit
into the body cavity of an adult of the size that is (apparently)
represented by the skull on top of >the nest. It seems less likely, though
certainly possible, that precocial young would still be in the >nest after
such a large amount of growth. I therefore think it more likely (though
hardly air-tight) >that the young were born closer in size to the that
represented by the preserved animals, and >they came from different
mothers. If we find complete eggs, it will obviously be easier to answer
>this question (because birth size will be constrained).
Good theory. I would even buy into semi-precocial psittacosaurs. They could
have fairly large eggs, belonging to multiple females.
As for the rushing water making a hole around the animals
hypothesis...maybe, but the fine->grained lithology argues against such a
high-energy depositional environment. Also, while there is >no color
change to easily indentify the nest surface, the animals do seem to be
physically >interacting with (e.g. their bodies conform to) a nest-shaped
I thought that maybe there was rushing from the way they were said to be
holding their heads up. As you have said after seeing it live, this does
look like a nest grouping, even from the photograph. If this is a nest, and
there was no transport, shouldn?t there be some eggshell? Or is there?
Hope that clarifies what I know about the specimen, as well as what I don't
know (lots, alas).
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