Re: [erect posture and its implications]

[archosaur@usa.net]

owner-dinosaur@usc.edu wrote:
> Message text written by INTERNET:cadams@hh.gpz.org
> >regulation<
> 
> Perhaps vertical height (and mass?) is only possible with a four chambered
> heart.....a 4 C heart permits more vigorous activity and once acquired
> enables size.....
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What about Megalania prisca? Or Testudo atlas? 
Both grew to be large animals and both probably 
retained the three chambered heart.

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> I suspect that a higher metabolism is advantageous in that it permits
> migration, leading to ability to continuously exploit available food
> sources, leading to occupation of all available ecological niches,
> squeezing out the less effiicient more reptilian fauna. How many modern
> reptiles can migrate long distances...turtles, what else?
> 
> I also suspect this idea is not new.
> 
> martin

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Crocodylus palustris and Crocodylus niloticus
are both known for traveling huge distances over
land in search of better territory. I believe that 
C.palustris was recorded at 15 miles from one water
source to another.

Crocodylus porosus and Crocodylus acutus make oceanic
journeys in search of better feeding grounds.

And that's just crocodilians. Galapagos tortoises travel
many miles to communal nesting grounds and communal grazing 
grounds. 

Same for galapagos land iguanas too.

And then there are all those little herps that make huge
(comparitively) treks to their nesting grounds.

Just because most extant reptiles are small, doesn't mean 
that they don't migrate long distances.

Archosaur J

"Fight the Future. Beat up Psychics!"


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