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Re: Ornithischian Metabolism (was "New Ref")



MarkSabercat@aol.com wrote:

> Ecologically, basal ornithischians and early sauropodomorphs were likely
> prey for at least some basal theropods, a stituation that would later have
> included hypsilophodontids, hadrosaurs, thyreophoreans, sauropodomorpha and
> ceratopsians. Any prey species must be at least as fast and/or agile as its
> predators, or go extinct. Basal ornithischians and sauropodomorphs would not
> have survived and radiated if their thermal physiology had not been on the
> same grade as that of coelurosaurs and even earlier saurischians.

Rant begins.

Would you also suggest that worms are as fast and/or agile as birds? I
wouldn't! Yet birds have not driven worms to extinction. Sometimes being
well camoflauged or otherwise hidden from view, or being smart enough to
develop avoidance strategies, can put metabolically disparate species on
an even footing.

How about plants? Are they as metabolically active as the herbivores
that prey upon them? Maybe African strangler vines, or triffids... :)

Safety in numbers can also sway the odds of individual predation. I
can't see an indivual krill out-running or out-metabolising any of their
predators. And parrot fish haven't driven any coral species into
extinction, as far as I'm aware. 

One creature doesn't need an equal metabolic status to prey upon
another, or to avoid being preyed upon. Dumb ectothermic Great White
sharks manage to catch bigger-brained, endothermic pinnipeds. Metabollic
status is not the be-all and end-all of survival.

Rant ends.

-- 
________________________________________________________________

Dann Pigdon                   Australian Dinosaurs:
GIS / Archaeologist         http://www.geocities.com/dannsdinosaurs
Melbourne, Australia        http://www.alphalink.com.au/~dannj/
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