Re: Turtles and dinosaur predators (Re: Oviraptorids as Parrots?)

[Phil Bigelow <bigelowp@juno.com>]

Stopping to bend down and snarf up a land tortoise may not have been
worth the expenditure of a tyrannosaur's energy.  A 1+-meter _ Basilemys_
probably weighed around 400 pounds, and some of that was bone, not
protein.

OTOH, if large predatory dinosaurs occasionally ate _Basilemys_ whenever
the opportunity presented itself, it could have had a significant effect
on the tortoise's population.  Modern mega-tortoises (e.g., Galapagos)
don't exactly breed like bunnies.

It would be helpful to find a _Basilemys_ carapace with tyrannosaur tooth
puncture marks.

<pb>
--

On Mon, 06 Feb 2006 09:24:34 +1000 dannj@alphalink.com.au writes:
> On Sun, 05 Feb 2006 14:55:18 -0800 (pst), Phil Bigelow wrote
> > To a tyrannosaur, chasing and eating a land tortoise is like a 
> human
> > running-down and eating a pie that is sitting on a picnic table. 
> >  How did these (relatively immobile) land creatures avoid 
> predators 
> > with a bite force of over a ton per square inch?
> 
> Sam Neil wandered about the Cretaceous landscape, telling the 
> tortoises 
> to 'stand still'. :)
> 
> Seriously -- you might as well ask how ostriches ever manage to 
> incubate 
> their eggs, or how new-born gazelles don't all get found and eaten 
> by hyenas.
> 
> Predators tend to be pretty thin on the ground, so when you're a 
> small(ish) 
> animal in a big landscape, the chances of a predator happening to 
> cross your 
> path is probably fairly small. If the prey species in question 
> happened to 
> look a lot like a rock, and spent a lot of time staying still, even 
> a 
> Tyrannosaur who's vision isn't based solely on movement (ie. almost 
> certainly 
> all of them) might not notice the tortoise.
> 
> --
> ___________________________________________________________________
> 
> Dann Pigdon
> GIS / Archaeologist         http://heretichides.soffiles.com
> Melbourne, Australia        http://www.geocities.com/dannsdinosaurs
> ___________________________________________________________________
> 
> 
>