[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: attack on dinosaur--horrific video





--- john bois <jbois@verizon.net> wrote:

> 
> ----- Original Message ----- 
> From: "Andreas Johansson" <andreasj@gmail.com>
> To: <dinosaur@usc.edu>
> Sent: Thursday, November 22, 2007 9:32 AM
> Subject: Re: attack on dinosaur--horrific video
> 
> 
> > Well, it should lead us to the conclusion that
> nest predation can't be
> > all that bad even for night-blind species: else
> ostriches would have
> > been exinct long ago.
> 
> _All_ continental ground nesting birds depend on
> concealment not 
> defence--the nests are indefensible at night. 
> Darwin talks about having to 
> practically ride _over_ Rhea nests before
> discovering them.  Bertram talks 
> about the total invisibility of ostrich nests beyond
> ten metres distance. 
> The question for mesozoic comparison is: could large
> dinosaurs lacking the 
> cover of prairie and savannah grasses, hide? 
> Surely, they could in forested 
> areas--but then they would have to deal with the
> attendant greater diversity 
> and numbers of critters that live there.  One of the
> secrets of ostrich 
> success is great concealment and low predator
> density of arid grasslands. 
> 
> 
 
The outer eggs in an ostrich clutch are false/duds and
will not produce young. Lions finding an ostrich nest
will destroy a few in their initial excited frenzy but
are then powerless to break open any more after that.
The valuable eggs are usually spared. 

Would dinosaurs have had false eggs? Super thick eggs
would seem valuable against smaller egg thieves but
couldn't create an egg a large carnosaur couldn't
crush and eat. 

I tend to think that dinosaurs ran the gambit when it
came to clutch protection. 

d simpson

HAPPY THANKSGIVING

I'm thankful for fossilization!!!!






      
____________________________________________________________________________________
Never miss a thing.  Make Yahoo your home page. 
http://www.yahoo.com/r/hs