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Re: my working hypothesis for body size



Thomas R. Holtz, Jr. wrote:

> So, how do we calculate average size?  Average maximum size of adults?  That
> would seem to be the easiest way, and could indeed be the most significant.
> 
> Average size within a population?  Our (admittedly limited) knowledge of
> dinosaur growth and populations seems to indicate something very different
> for dinosaurs than for mammals or birds.  In a mammal or bird flock, there
> are a few young and a LOT of full grown individuals.  It looks as if
> dinosaurs, as r-selectors (that is, organisms that produce a LOT of young,
> most of which died before adulthood) had populations where a substantial
> part were not fully grown, and only a small fraction were maximum size.
 

Is either even possible?  Statiscally in modern animals, say elephants,
the largest animals are few and far between.  But they are really,
really bigger than the ordinary, run-of-the-mill individuals (say, the
record stuffed-and-mounted tusker in the Smithsonian compared to any 5
Ringling Brothers African elephants or any 2 African elephants in the
Cleveland zoo).  Would the preservation bias of fossilization even come
close to allowing us to sample a true number of average maximum-sized
individuals?

-Betty Cunningham