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Re: Segregated vs age-mixed sauropod herds



 Sauropods and their nests were many times bigger than sea turtles.

So?

 Many (most?) sea turtles lay their eggs at night--I don't know if
 this would be practical for a Titanosaur!

Why?

 I don't know that any dinosaurs had abilities that would have afforded
 them the same separation from their predators.

Egg Mountain and Egg Island -- the *Maiasaura* nesting sites -- were islands in a lake, weren't they?

 Such profligate reproduction would not be possible for sauropods.

Not only would it be possible unless I'm overlooking something sauropod-sized, it seems to be what we're seeing. The eggs found so far are absolutely tiny compared to the adults, and plentiful indeed.

 In any case, the trend in amniotes seems to be toward the evolution
 of more not less parental investment in offspring--or, should I say,
 investment in fewer high quality babies.

Assuming trends is very easy; detecting trends is pretty difficult. And when it is done, the results are usually negative (witness the crumbling of Cope's "rule").

What kind of selection pressure, coupled with what kind of slow mutation rate, could generate such a trend across hundreds of millions of years?