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Fwd: David Button Sauropod reproductionb



>
> How did sauropods get so big? Article  + radio interview with David Button :
>
> http://www.abc.net.au/radionational/programs/scienceshow/how-dinosaurs-grew-so-big/6816224


Ignored in this discussion is the idea that sauropods reached extreme
size because of the need to defend the nest, i.e., at nesting time
guarding parents are locked at one location and are easy pickings for
larger predators.
Button instead claims the following:
- Sauropods laid many separate clutches in shallow nests
       - this defies the logic of predation: eggs are a desirable
resource and multi tonne egg layers could not oviposit in secret
        - also ignores evidence of likely colonial nesting right?

- Sauropods left hatchlings to their own fate
        - sauropods could not distance themselves from predators as
well as birds...therefore their nests and hatchlings must have been
amid relatively higher predator density. The argument is that they had
more of a reptilian style, but: snake and lizard babies hide down
holes; crocodilian babies have parental protection and hide in aquatic
habitat; turtle babies have a shell and after running terrestrial
gauntlet, sea turtles escape to marine protection. So it is hard to
imagine anything similar for sauropod babies.

- Sauropod babies did not have parental protection: "Some did, some did not."
     -I would say this assumption is unsupportable. It is difficult to
demonstrate parental investment...it is equally difficult to
demonstrate _no_ parental investment.

So we are left with the idea that sauropods practiced a lay-and-leave
strategy like sea turtles: have so many offspring that the predators
can't keep up. I contend this can only work in areas of low predator
density...for example turtles generally swim to remote places and
swamp the few predators that are present.