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RE: How Did Hadrosaurs Survive? (Was: Hadrosaur "mummy" questions)




From: "Williams, Tim" <TiJaWi@agron.iastate.edu>
To: "'Tim Donovan '" <msdonovan66@hotmail.com>
CC: "'dinosaur@usc.edu'" <dinosaur@usc.edu>
Subject: RE: How Did Hadrosaurs Survive? (Was: Hadrosaur "mummy" questions)
Date: Mon, 28 Oct 2002 14:22:28 -0600


Tim Donovan wrote:

>  I don't think so; it seems far more likely that hadrosaurs fled, and
> fought only as a last resort.

That's bad news for hadrosaur babies sitting in the nest: "Sorry kids,
you're on your own.  Gotta run!"

Baby hadrosaurs weren't worthwhile prey for tyrannosaurs. Troodont teeth have been found in association with hadrosaur nests, but no tyrannosaur teeth AFAIK.



> If hadrosaurs had regularly attempted to stand their ground, weapons > and or armor would have been selected for. Instead they evolved keen > senses and longer legs, and "hooves".

I would hypothesize that large body size is a defense against predators.
Don't forget that the adult body size of certain hadrosaurs (c. 15-16m)
overlaps with certain contemporary adult titanosaurs.

But titanosaurs were armored, hadrosaurs were not. Unless an herbivore is gigantic, it should have armor or weapons if it attempted to stand its ground.




That's pretty darn
big, and what tyrannosaur would be foolish enough to tackle a herbivore at
least as big at itself.

What hadrosaur would be foolish enough to fight a predator of comparable size without any obvious weapons?



It only takes a broken ankle to disable a
tyrannosaur and severely reduce its chances of success at its next attempt
at predation.




Tim


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