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Re: individual age



Just adding my two cents as well:

    Anusuya Chinsamy is the best source so far for the LAG detection in
dinosaurian bone, even with Haversian canals.  Her best guess for
_Massospondylus_ ages is around 17 years (fully grown).  Most of her dinos
seem to die in the 13 to 24 year range - IF each line indicates ONE year.
    (In discussion with her some time ago (back when she was in Phila.), she
indicated the Haversian systems showed quite a bit of bone reworking -
distinquishing that from the lines was her greatest problem, outside of
determining the periodicity of each line).
    Of course, some bones do not show any lines still extant, and therefore
we cannot tell one way or another.  So - some sauropods may have lived for
80-100-150 years - or maybe even 1200 years!!!  (However, some lifecycle
analysis has indicated that anything past 130 years is highly unlikely).

    (As to the poor lizard in the afore-mentioned treadmill experiment - yes
it did develop Haversian canals - which seems only to indicate a need for
high-vascularization in a high metabolic condition.  If any animal needs a
good blood supply (for whatever reason), Haversion canals fit the bill).

    Allan Edels


-----Original Message-----
From: BHinchSaur <BHinchSaur@aol.com>
To: znc14@TTACS.TTU.EDU <znc14@TTACS.TTU.EDU>
Cc: dinosaur@usc.edu <dinosaur@usc.edu>
Date: Thursday, January 15, 1998 3:13 AM
Subject: Re: individual age


>In a message dated 98-01-14 13:40:23 EST, you write:
>
><<         As long as they were formed in regular time increments they are
at
> least minimally useful in providing an absolute (although indecipherable)
> timing mechanism. >>
>
>I agree  that these may be used as comparisons, my point was that the
period
>is not known, and therefore age other than in a relative sense, is not yet
>determinable.
>
><and others still show signs of a Haversian Canal system, a marker for
> Endothermy.>
>You wrote:
>        << Recent experiments suggest that this is really a marker for high
> activity levels. I believe they ran some poor unfortunate lizard on a
> treadmill for a very long time and observed Haversian systems in its
bones.
>:)
>  >>
>Now that you jog my memory I do recall reading of anexperiment of this
nature,
>if I should com across it I will certainly post it.
>
>Bill Hinchman
>