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RE: attack on dinosaur--horrific video



Sorry but I cant square an isolated incident of mammalian predation on
dinosaurs as evidence for the extinction on non avians.

-----Original Message-----
From: owner-DINOSAUR@usc.edu [mailto:owner-DINOSAUR@usc.edu] On Behalf Of
john bois
Sent: 25 November 2007 02:30
To: dinosaur@usc.edu
Subject: Re: attack on dinosaur--horrific video


----- Original Message ----- 
From: "Andreas Johansson" <andreasj@gmail.com>
To: <dinosaur@usc.edu>
Sent: Saturday, November 24, 2007 6:10 PM
Subject: Re: attack on dinosaur--horrific video


> Shouldn't we also see a driven trend to larger size in Cenozoic
> oviparous amniotes?

My point is that today, at least, this strategy is not viable...otherwise we

would, indeed, see it.  But crocs are the _only_ oviparous species that 
"choose" defense over concealment and remote laying.  Concealment carries 
selection on _small_ size; whereas remote laying selects for long distance 
flying.

> I'm not seeing why egg-predation by placentalians would affect
> mesozoic dinosaurs differently from other egg-laying amniotes.

Not just placentals...but, anyway...birds can conceal and fly to 
out-of-the-way places; crocs are just special; snakes and lizards conceal 
(usually); turtles generally lay in out-of-the-way places and swamp 
predators.