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Re: questions about the Odontochelys study



I would also say, perhaps the plastron reduction, even when permitting
enhanced limb motility (which I do not view as a great advantage,
given that these turtles do not need to be upright to feed with their
long necks and jaws, and to walk the common way of other aquatic
turtles with a more developed shell coverage would suffice), was not
an adaptation acquired through natural selection.

The snapping turtle is too agressive, the matamata well camouflaged,
so perhaps the shell is less necessary for those turtles in defense.
Then, perhaps if the carapace reduced a little, there was not such a
great problem. I think carapace reduction perhaps is just result of an
heterochronic process, of lack of development, and that can (or not,
being relatively neutral) fix into populations if the pressure of
predation is not so big. These pressures can be great for
non-aggresive, non camouflaged, and small turtles, but not so much for
others.