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Re: A note on pterosaur nesting behavior
On Jul 24, 2009, at 7:29 AM, David Peters wrote:
Imagine a bat baby buried.
The wear and tear on the wing and hind limb membrane as it escapes
its burial chamber would be problematic.
I'm not sure that's actually true, and even if it is, it may not be
applicable to pterosaurs, which seem to have possessed a wing membrane
with rather different material properties from those of bats. There
are living bats that dig and scramble around on the ground, so
membrane wings are not as much a hazard as it might seem.
While all fossils are buried, the indications of the present three
embryos do not indicate intentional burial.
If buried, evidently pterosaurs buried their eggs one at a time.
This could be the case, but why do you think that need be true?
If lepidosaurs, the eggs could have been laid within a short time of
hatching, which is the present indication.
Life history variables are often quite plastic; I would hypothesize
that a short incubation time would be possible for many potential
phylogenetic positions. Some birds have quite short incubation
times. Lepidosaurs take it even further, of course, with ovi-
viviparity and the like, but I would argue that the possible
incubation and nesting parameters has more to do with egg structure
and physiology than phylogenetic position (except to the the extent
that egg morphology happens to be phylogenetically constrained - which
is rather complicated).
Michael Habib, M.S.
Center for Functional Anatomy and Evolution
Johns Hopkins School of Medicine
1830 E. Monument Street
Baltimore, MD 21205