Re: gigantism as liability

[john bois <jbois@verizon.net>]

----- Original Message ----- 
From: "Graydon" <oak@uniserve.com>
To: <dinosaur@usc.edu>
Sent: Saturday, November 08, 2008 9:42 PM
Subject: Re: gigantism as liability


> >> There are plenty of examples of small predators picking on
> > large...mice on albatross, armadillos on rhea, black-backed jackal on
> > ostrich, monitor lizards on Nile crocs.
>
> These are all at most a single order of magnitude typical difference.
> (Maybe two in the case of the monitors and the crocs.)
>
> It makes parent/nest predator interaction practical.
>
> What you're proposing is that the ~10 kg and ~100 kg nest predators were
> defended against by the ~20 tonne parents, defending the nest.  How?

I meant to add: The most vigorous selective force for large size would come 
on adults--being uanable to run away without giving up considerable 
reproductive investment (and this investment might include migration cost, 
mating competition, etc., etc., and not just the few lousy calories present 
in the eggs at the time)--the sauropods must face direct predation. This is 
a much greater "incentive" for n.s., than predation on eggs and babies 
alone. Maybe the biggest were beyond fear in this regard, I doubt it.