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Re: tyranno growth
On Tuesday, August 17, 2004, at 12:36 AM, GSP1954@aol.com wrote:
Took a look at the tyranno growth paper. The authors note that the
estimates based on femoral circumferance are conservative. Indeed. The
for Tyrannosaurus is just a little low, but those for the others are
low by a
factor of two or more. Gorgosaurs, albertosaurs and daspletosaurs were
large tyrannosaurs whose volume shows they massed about 2.5 tonnes. No
were only one fifth the size of Tyrannosaurus, at the mass of wee
example of the perils of using limb bone circumferance as indicators
the relationship between the two being highly inconsistent.
One thing that's been bothering me about this study since it was
released is the growth ring theory. Can anybody here explain exactly
what causes growth rings? To my understanding, the prehistoric[or at
least, before the most recent ice age] climate was pretty much warm all
year round. The trees that we co-exist with are subject to changing
seasons including winter, when as far as I know growth stops/halts,
only to resume in spring. Is it this stop/go growth that causes the
'growth rings'? If so, then one could see how counting rings from a
creature that lived in a presumed fairly constant ecologic environment
could be prone to error.
I'll just sit back and wait now for someone to disprove what I've just
said - I love the scientific pursuit of truth.