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Delayed "growth spurt" in T. rex
Anyone care to speculate on why the "growth spurt" phase in the _T. rex_
young occured 10 years AFTER the animal's birth? Logically, such a
growth spurt would have taken place from birth through adolescence.
Are there any modern analogs to this developmental style?
On Wed, 11 Aug 2004 14:37:41 -0400 "Thomas R. Holtz, Jr."
> Where are the old tyrants?:
> The reason may be related to something that Carrano & Janis, Paul,
> others have noted before: that non-avian dinosaurs were more r-
> K-selectors in terms of ecology. That is, their much higher rate
> replacement (a dozen or more eggs per clutch, as opposed to a
> offspring in 2 or more years for elephant-to-indricothere sized
> would mean that tyrant populations could be maintained without
> having to
> have long-lived adults. (And the same is true for all large bodied
> dinosaurs). In contrast, large-bodied mammals would need to live for
> durations in order to ensure a sufficient number of young in a
> So natural selection can favor long-lived placentals where the same
> type of
> selection would be weaker on big dinos. Large dinosaurs appeared to
> grown fast like mammals, but don't appear to have their long
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